Applied Mechanics and Materials Vol. 575

Abstract: Natural fiber composites are getting much attention by researchers and industries. Natural fiber composites face the problem of incompatibility between fibers and polymers. Alkali treatment is the most common treatment for natural fiber composites. In this work, short “Kenaf (Hibiscus Cannabinus) Fiber” (KF) reinforced “Themoplastic ‎Polyurethane (TPU)” was prepared using Haake Polydrive R600 ‎internal mixer. After mixing, sheets for specimen cutting were prepared by compression molding. The aim of this work is to study the effect of alkali fiber treatment on stress-strain behavior of TPU/KF composites. Different alkali concentration was used, namely; 2, 4 and 6% NaOH. Tensile stress and strain were deteriorated with increase in NaOH concentration, while modulus increased slightly.

Abstract: The objectives of this study are mainly focusing on reviewing the potential of membrane bioreactor application in Batik dyes degradation and to identify the factors contributing to the permeability and selectivity of a membrane-coupled bacteria reactor. It is evidently that integrating membrane technology with biological reactors for the treatment of textile dyeing wastewaters has led to the development of three generic membrane processes within bioreactors: for separation and recycle of solids, for bubble-less aeration of the bioreactor, and for extraction of priority organic pollutants from hostile textile dyeing wastewaters. Thus, installation costs and usable floor area of the infrastructure are saved, due to the separation unit of MBR replaced the sedimentation basin that is used in current practice. It is well recognized that east coast states in Malaysia such as Kelantan and Terengganu are the main producers of “Batik” industries in which create a huge contribution to Malaysia textile economy development due to high demands from local and abroad. Batik textile wastewater is a complex and consist highly variable mixture of many polluting substances including dye. Existence of dyes in the wastewater plays a major issue and has raised significant concerns. Thus, selection of microorganism and the separation processes of the membrane bioreactor are vital to be evaluated towards an achievable productivity and efficient process separation. These are depended on several factors which include degradation of dye, temperature, retention time, pH and concentration of the textile wastewater.

Abstract: Effect of calcination temperature on the synthesis of N, Fe codoped TiO₂ for the photodegradation of methylene blue under ordinary visible lamps was investigated. The photocatalyst were prepared using solgel method where titanium isopropoxide was used as precursor of titania. The calcination temperatures were varied from 450 to 600°C. The prepared photocatalysts were characterized by using XRD, FE-SEM and FTIR to determine their physical properties. The results from XRD proved that photocatalysts calcined at 600°C possessed perfect properties in phase and crystal size. FE-SEM image analysis revealed the formation of the fine spherical particles and the FTIR analysis verified the presence of dopants at various calcination temperatures. The effectivity of photocatalysts was tested by performing a standard batch photocatalytic degradation experiment with methylene blue as a model pollutant under ordinary visible light. The result showed that N and Fe codoped photocatalyst calcined at 600°C (1.0 % N, Fe-TiO₂-600) yielded a maximum of 80.50% methylene blue degraded within five hours of irradiation time.

Abstract: Enlargement of textile industry in Malaysia is swiftly growing as it plays vital role in human evolution by providing cloths. Industrialization in textile fields plays main part in colouring of fabric as it gives environmental concerns associated with textile effluent. The usages of dyestuff make textile effluent difficult to biodegrade as the complexity of chemical structures of dyes. The diversity of forestry creates nature plant such as bamboo which is used as mediator in dye decolorize of textile effluent. As sustainable resolution can reduce environmental system destruction, the effectiveness and competency of bambusa heterostachya has been investigated to analyze the potential in decolorize of textile effluent. The result exhibited good dye decolourization rate of 70 - 80 % in less than 72 hours with influence studies.

Abstract: The use of thermoplastic elastomers (TPE) in making parts of the vehicle such as a weather strip at the door and car window, floor mat, and dashboard is widespread. The commonly being used as in automotive parts manufacturing is styrene based TPE. Styrene based TPE released harmful gas, volatile organic compound (VOC) to the environment when it expose to the high temperature. Therefore, the new material with properties of thermoplastic elastomers is made from Natural rubber blend with local Tacca leontopetaloides starch and silica extracted from rice husk (as filler). Investigation on the mechanical properties by using Universal Testing Machine (UTM) found that the green material produced has potential to replace the existing floor mat used in automotive production. Indeed, when the starch was plasticized by glycerol and the volume of Natural rubber was varies, the value of tensile strength of green material produced was higher compared with existing floor mat. The VOCs released when its expose to the high temperature was much lower than the existing floor mat used. On top of that, Tacca leontopetaloides starch has potential to create low cost of new green materials in manufacturing of automotive parts.

Abstract: The current trend in the industry is to produce thin, light weight, and environmental products. In this project, flat or shallow thin-walled parts were designed and moulded lignocellulosic polymer composites (PP + 50 wt% wood) to visualize the processability via moulding simulation. This studied focused on the filling, shear stress at wall, and in-cavity residual stresses behaviors. The shallow thin-walled part is preferable in moulding PP + 50 wt% wood due to economically in processing, low shear stress distribution and low residual stresses than the flat thin-walled part.

Abstract: The success of metal injection moulding (MIM) process is significantly influenced by the homogeneity level of the powder-binder mixture (feedstock). This paper highlights some initial characterization of the feedstock containing elemental Ni and Ti powders mixture, (50.8 at.% Ni/ 49.2 at.% Ti) mixed with Palm stearin-based binder system. The feedstock was prepared using an internal mixer, HAAKE Rheomix at a temperature of 160°C for 2 hours. The feedstock was then characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric (TGA), Scanning Electron Microscopy (SEM) and Capillary Rheometer. All the results obtained were analyzed and discussed for further injection moulding process.

Abstract: This research aims to develop an aluminum alloy suitable for applications in the nuclear industry, particularly in terms of its hardness. A synthesized AlFeNiMg alloy plate was subjected to deformation in a gradual rolling process at room temperature. A Vickers hardness tester and an optical microscope were employed to analyze the hardness and to observe the microstructure of the aluminum alloy consecutively. Analyses of elements and phase structures were performed by EDS-SEM and X-ray diffraction. The result shows that the hardness of AlFeNiMg alloy increases along with the increase in rolling deformation. The alloy hardness increases from 88 HV to 113 HV, 135 HV, 153 HV and 165 HV at percent cold reduction of 30%, 53%, 65% and 88% consecutively. From the microstructure observation, the grains tend to get more elongated along with increasing rolling deformation. The pattern analysis of X-ray diffraction shows that there are two phases, namely α and θ (FeAl₃).

Abstract: Experiment in the making of U-ZrH_x powder at Zr content variation for PWR reactor fuel has been carried out. At first, U-Zr ingots was made with Zr content of 35wt% (U-35Zr), 45wt% (U-45Zr) and 55wt% (U-55Zr). Then U-Zr ingots were used to make U-ZrH_x powder through hydriding technique. Hydriding process carried out at temperatures of 450° C with vacuum pressure of 14.80884 x 10^-3 psi and under hydrogen gas flowing for 10 hours. Then U-ZrH_x powders were tested to determine the characteristics such as density, heat capacity, and morphology. The test results showed that the density of the U-ZrH_x decrease with increasing Zr content. The density are 10.4256 g/cc, 8.000 g/cc respectively, and 7.0359 g / cc for U-35ZrH_x, U-45ZrH_x and U-55ZrHx alloy. The heat capacity test results showed that the highest heat capacity is achieved at U-45ZrH_x alloy powder that measured up to temperature of 437° C that is equal to 0.37J/g.°C. When observed from the test temperature, indicate that the heat capacity value for each sample examination decrease with increasing the test temperature. Meanwhile, the powder morphology examination result showed that all the U-ZrH_x powder sample have a flat shape, irregular and tend have the smaller particle with higher increasing the Zr content.

Abstract: 5wt% Co deposited on a support catalyst Ce_0.75Zr_0.25O₂ mixed oxide were prepared by combination of microemulsion and deposition-precipitation method followed by calcinations at temperature 500°C. The microemulsion component comprise of cetyl trimetyl ammonium-bromide (CTAB), 1-butanol, n-octane and aqueous solution. Sodium hydroxide (NaOH) was used as precipitation precursor for the preparation of water-in-oil microemulsions method. The particles were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption analysis and Field Emission Scanning Electron Microscopy (FESEM). The results showed the preparation method has significant influences on the textural and structure properties of Co/Ce_0.75Zr_0.25O₂. The formation of Co/Ce_0.75Zr_0.25O₂ inhibit the better performance based on the particles size, specific surface area and particle distribution of cobalt into Ce_0.75Zr_0.25O₂.