Applied Mechanics and Materials Vol. 695

Abstract: Solid oxide fuel cells (SOFC) are an efficient and clean power generation devices. Low-temperature SOFC (LTSOFC) has been developed since high-temperature SOFC (HTSOFC) are not feasible to be commercialized because high in cost. Lowering the operation temperature has caused substantial performance decline resulting from cathode polarization resistance and overpotential of cathode. The development of composite cathodes regarding mixed ionic-electronic conductor (MIEC) and ceria based materials for LTSOFC significantly minimize the problems and leading to the increasing in electrocatalytic activity for the oxygen reduction reaction (ORR) to occur. Lanthanum-based materials such as lanthanum strontium cobalt ferrite (La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ) recently have been discovered to offer great compatibility with ceria-based electrolytes to be applied as composite cathode materials for LTSOFC. Cell performance at lower operating temperature can be maintained and further improved by enhancing the ORR. This paper reviews recent development of various ceria-based composite cathodes especially related to the ceria-carbonate composite electrolytes for LTSOFC. The influence of the addition of metallic elements such as silver (Ag), platinum (Pt) and palladium (Pd) towards the electrochemical properties and performance of LSCF composite cathodes are briefly discussed.

Abstract: This paper presents the application of different imaging techniques for viewing the internal structure of rubberized asphalt mixture as road materials. Two imaging techniques were used to capture the internal structure images of its compacted samples i.e. X-ray Computed Tomography (non-destructive method) and Scanning Electron Microscope, SEM (destructive method). Since a lot of previous researchers have produced extensive works on the mechanical properties, therefore, this study is an attempt to introduce the microstructure of rubberized asphalt mixtures produced using dry process method. Two types of dry mixed rubberized asphalt mixture were prepared by modifying a Hot Rolled Asphalt Mixture (HRA 60/20) with different crumb rubber sizes. A mixture of conventional HRA 60/20 was also scanned for comparison. The illustrations are aimed to provide the researchers more information regarding their internal structure distribution.Keywords: Imaging techniques, X-ray Computed Tomography, Scanning Electron Microscope, Rubberised Asphalt Mixture

Abstract: Biochar was produced from oil palm shell via microwave-induced pyrolysis. The biochar was subsequently activated via microwave assisted CO₂ activation. A simple single layer arrangement of the microwave absorber (coconut shell based activated carbon) and oil palm shell in the reactor was adopted during pyrolysis. In recent times, the treatment of oil palm biomass using microwave heating technology has been on the increase. Value added products such as bio-oil, gas, biochar and activated carbon are being produced while at the same time serving as waste management control. Biochar is seen as a promising climate mitigation tool. Activated carbons can be used as absorbent for the removal of pollutants from wastewaters, as air pollution control and as electrode for supercapacitor. This paper presents comparative study between the characteristics of oil palm shell biochar and oil palm shell activated carbon. BET surface area and Scanning Electron Microscopy (SEM) were analyzed to establish the characteristics of the biochar and activated carbon.

Abstract: Selective Catalytic Reduction catalyst (Cu-Mn/CSC) was derived from coconut shell carbon (CSC). The bimetallic catalysts, Copper and Manganese (Cu-Mn), were deposited onto CSC using wet impregnation technique while the calcination stage was performed under low temperature ambient air. The samples were then characterized using nitrogen adsorption-and-desorption, carbon dioxide temperature-programmed desorption, ammonia temperature-programmed desorption, hydrogen temperature-programmed reduction as well as scanning electron microscopy. The results showed that the synthesis process increased the external surface area and regulated the distribution of slit-shape pores on Cu-Mn/CSC. Besides, Cu-Mn was found to be reduced and the surface has more acidic groups compared to basic. These findings indicated the potential of using CSC as a precursor for NOx-Selective Catalytic Reduction catalyst.

Abstract: In this study, the Taguchi method was utilized to determine the optimum process parameters for dissimilar friction stir welding between AA6061 and AA7075 aluminium alloys. The Taguchi L9 orthogonal array and optimization approach was applied on three levels of three critical factors, namely rotational speed, transverse speed and tool tilt angle. The optimum levels of process parameters were determined through the Taguchi parametric design approach. Through the parameter analysis, the predicted value of the dissimilar joint’s tensile strength was calculated to be 209.7 MPa, which is in close proximity to the experimental data (219.6 MPa) with 4.5% error. It can be concluded that a high tensile value of 219.6 MPa was achieved using 1000 rpm rotational speed, 110 mm/min travel speed and 3 ̊ tilt angle.

Abstract: Improvement of construction industry will contribute to the economy of Malaysia because it is one of the five sectors used to calculate the national GDP. This fact is encouraging the Construction Industry Development Board (CIDB) of Malaysia to prepare many development plans like Roadmap 2003-2010, CIMP 2006-2015, and Roadmap 2011-2015. Adoption of the Industrialized Building System (IBS) is the step stone for all these plans. CIDB has created an indicator to assess the degree on industrialization for applied building system; IBS score. Furthermore, CIDB has specified the minimum values of this score for the building projects of government and private sector. This paper discusses the effects of adjusting these values on the structural design of an office building. The CIDB method of calculating the IBS score, the moment distribution method of structural analysis and BS8110 code of design will be used to analyze the selected case study.

Abstract: Discharge of heavy metals from metal processing industries is known to have adverse effects to the environment. Conventional treatment technologies for removal of heavy metals from aqueous solution are not economical and generate huge quantity of toxic chemical sludge. Biosorption of heavy metals by metabolically inactive non-living biomass of microbial or plant origin is an innovative and alternative technology for removal of these pollutants from aqueous solution. Therefore, in this study, it is aimed to investigate the potential of pandan leaves as a biosorbent to remove heavy metal, copper. The pandan leaves were extracted via solvent extraction method. The effect of dosage of biosorbent, pH aqueous solution, and the biosorption contact time towards removal of copper (Cu²⁺) ions were studied. The concentration of copper ions was analyzed by using atomic adsorption spectroscopy (AAS). The maximum biosorption of Cu²⁺ ions was obtained up to 70 % for 5ppm of initial copper ions loading by 1 hour.

Abstract: In this paper sustainable analysis is performed due to the increasing demand for fuel efficiency. Current research focuses on high strength-light weight components in automobile which lead to the development of advance material parts with improved performance. A specific class of advanced material which has gained a lot of attention due for its potential is aluminium based metal matrix composites (Al-MMCs). Al-MMCs have some prospects for several applications in automobile parts. The analysis in this paper is a part of product development which plays a crucial role in determining a product's environmental impact. The objective was accomplished and thus to identify the potential of Al-MMCs rake disc for replacement of the conventional cast iron brake disc. The result indicated that the Al-MMCs have the potential to substitute the cast iron brake disc.

Abstract: This study was to investigate the relationship between fibre length and composition of fibre inside the composite. In this study, three different fibre lengths were used namely 1cm, 1.5cm and 2cm; filling in various kenaf fibre/polypropylene (K/PP) ratio composite with fibre composition range from 10% until 50%. Maleic anhydride (MA) was added as additive to improve bonding between filler and matrix which is 0.3g. Properties of composite were measured using hardness and density test. Dino lite was used to observe the bonding inside composite. After testing, author founds out that polypropylene will give impact on hardness when mix with maleic anhydrice. Kenaf fibre will affect density of composite when it is submerge in water during testing. Kenaf fibre will tends to absorbs water if it is not fully cover by polypropylene. Maleic anhydride was proved can improve strength of composite after added inside composite.