Universiti Teknologi Malaysia

About: Universiti Teknologi Malaysia is a education organization based out in Johor Bahru, Malaysia. It is known for research contribution in the topics: Membrane & Control theory. The organization has 21644 authors who have published 39500 publications receiving 520635 citations.

Development of rigid bio-based polyurethane foam reinforced with nanoclay

Abstract: Integration of organic nanoclay into bio-based polyurethane (PU) foam is a promising alternative to enhance the foam’s properties via green technology. In this paper, modified diaminopropane montmorillonite (DAP-MMT) nanoclay was introduced into palm oil-based PU foam at different weight loadings, namely, 0, 2, 4, 6, 8, and 10 wt.%, in order to investigate the effects on the mechanical and thermal properties of the foam. Several tests and characterizations were carried out to study the surface morphology, density, compressive strength and thermal stability of the foam. It was found that foam exhibited an exfoliated or intercalated microstructure based on the DAP-MMT contents. The X-ray diffraction analysis showed that below 4 wt.%, the foams displayed exfoliated structures while beyond the value, the foams exhibited the intercalated morphologies. Closed cells with different cell sizes were observed when the DAP-MMT contents were varied. Meanwhile, thermal stability and compressive strength of foams increased with increasing DAP-MMT contents up to 4 wt.%, as shown by thermogravimetry analysis and compression test, respectively.

Evaluation of asphalt mixtures incorporating electric arc furnace steel slag and copper mine tailings for road construction

Abstract: This study evaluates the suitability of using electric arc furnace (EAF) steel slag and copper mine tailings (CMT) as substitution for conventional aggregates used in pavements for roads and highways. Four mix designs containing EAF steel slag and CMT at different proportions were investigated. Mix 1 was 100% granite, Mix 2 consisted of 80% granite and 20% CMT, Mix 3 consisted of 80% EAF steel slag and 20% CMT while Mix 4 consisted of 40% granite, 40% EAF steel slag and 20% CMT. Marshall stability, moisture susceptibility, indirect tensile resilient modulus and dynamic creep tests were used to evaluate the laboratory performance of the mixtures. The findings reveal that substituting natural granite aggregates with CMT and EAF steel slag improved the performance properties of asphalt mixtures. The mixture containing 80% EAF steel slag and 20% CMT produced the best results. The resilient modulus results show that the resilient modulus of the mixes decreased as the temperature increased. Also, the aging process significantly increased the resilient modulus and dynamic creep modulus values. Thus, the study has revealed that the mining by-products (CMT) and metallurgical by-products (EAF steel slag) can be utilized as aggregates in road construction.

Design, implementation and performance of ultra-wideband textile antenna

Abstract: Communication technology is increasingly pervading everyday life. The rapid progress in wireless communication besides the increasing interest in wearable antennas and electronics in civil, medical, sport wear and military domains promises to replace wired- communication networks in the near future in which antennas are in more important role. Recently, there has been growing interest in the antenna community to merge between wearable systems technology, Ultra-Wideband (UWB) technology and textile technology. All these together have resulted in demand for ∞exible fabric antennas, which can be easily attached to a piece of clothing. In this paper, three difierent structures of UWB antennas using clothing materials and suitable for wearable application were fabricated and presented. The substrate of the designed antennas was made from jeans textile material, while radiating element and ground plane are made out of copper tape. The operating frequency of all three designs is between 3GHz and 12GHz. Measured results are compared with simulations and good agreement was observed.

Satellite Images for Monitoring Mangrove Cover Changes in a Fast Growing Economic Region in Southern Peninsular Malaysia

Abstract: Effective monitoring is necessary to conserve mangroves from further loss in Malaysia. In this context, remote sensing is capable of providing information on mangrove status and changes over a large spatial extent and in a continuous manner. In this study we used Landsat satellite images to analyze the changes over a period of 25 years of mangrove areas in Iskandar Malaysia (IM), the fastest growing national special economic region located in southern Johor, Malaysia. We tested the use of two widely used digital classification techniques to classify mangrove areas. The Maximum Likelihood Classification (MLC) technique provided significantly higher user, producer and overall accuracies and less “salt and pepper effects” compared to the Support Vector Machine (SVM) technique. The classified satellite images using the MLC technique showed that IM lost 6740 ha of mangrove areas from 1989 to 2014. Nevertheless, a gain of 710 ha of mangroves was observed in this region, resulting in a net loss of 6030 ha or 33%. The loss of about 241 ha per year of mangroves was associated with a steady increase in urban land use (1225 ha per year) from 1989 until 2014. Action is necessary to protect the existing mangrove cover from further loss. Gazetting of the remaining mangrove sites as protected areas or forest reserves and introducing tourism activities in mangrove areas can ensure the continued survival of mangroves in IM.