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Concrete failure will lead to serious safety concerns in the performance of a building structure. It is one of the biggest challenges for engineers to inspect and maintain the quality of concrete throughout the service years in order to prevent structural deterioration. To date, a lot of research is ongoing to develop different instruments to inspect concrete quality. Detection of moisture ingress is important in the structural monitoring of concrete. This paper presents a novel sensing technique using a smart antenna for the non-destructive evaluation of moisture content and deterioration inspection in concrete blocks. Two different standard concrete samples (United Kingdom and Malaysia) were investigated in this research. An electromagnetic (EM) sensor was designed and embedded inside the concrete to detect the moisture content within the structure. In addition, CST microwave studio was used to validate the theoretical model of the EM sensor against the test data. The results demonstrated that the EM sensor at 2.45 GHz is capable of detecting the moisture content in the concrete with linear regression of R2 = 0.9752. Furthermore, identification of different mix ratios of concrete were successfully demonstrated in this paper. In conclusion, the EM sensor is capable of detecting moisture content non-destructively and could be a potential technique for maintenance and quality control of the building performance.

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The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription.

Recently, due to its low cost there has been increased attention on Animal Waste Fats (AWFs) as a feedstock for biodiesel production. Advanced microwave technology has also been reported by many researchers to enhance the transesterification in biodiesel production. However, esterification of free fatty acids in the feedstock reported here has not attracted so much attention. AWFs come with its challenges namely, high free fatty acid (FFA) content and high water content. This study utilizes AWFs (tallow) containing very large amount of FFA; (25wt.%, 18 wt.%, and 9.4 wt.% FFA/AWFs) as feedstock for fatty acid methyl ester (FAME) production.A simple thermal pre-treatment technique followed microwave assisted esterification with methanol (MeOH) was conducted in a batch process to reduce the FFA content to as low as 1wt.% FFA, which is then suitable for the alkaline transesterification process. The pre-treatment of AWFs at 88°C to first reduce water and decrease viscosity, followed by an operating microwave power of 70W producing a power density 1.147mW/m 3 , achieved a 15% increase in reduction of FFA over 30W microwave power and conventional thermal method. Under optimum conditions, using 2.0 wt.wt% sulphuric acid catalyst/AWFs and 1:6 molar ratio AWF/MeOH, the FFA conversion of 93wt. % was achieved. The results indicated that the pre-treatment and microwave application provided a faster route to high FFA reduction of AWFs during esterification process. The proposed technology is promising for the potential scale up industrial application.

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No abstract

The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription.