Graphene oxide (GO) was prepared using metal-catalyzed crystallization of amorphous carbon on a carbon fiber surface to improve the mechanical properties of the carbon fiber (CF). The deposited GO was used for repairing of surface structure defects on CF, thereby improving the tensile strength and interfacial strength force of CF. The grown morphology of GO and the changes in CF surface microstructure before and after remediation were investigated in detail by scanning tunneling microscopy and Raman spectroscopy. The effects of surface repair on the mechanical properties of the CF and the resulting composites were investigated systematically. The results of scanning tunneling microscopy show that the graphene oxide formed on the surface of carbon fiber present uniform dispersion. Raman spectroscopy curves indicate that CF successfully remediated the defects in the CF surface. The results of mechanical properties testing show that such a remediation method could significantly enhance the tensile strength of CF and increase the interfacial strength versus raw fibers; that is, the tensile strength of CF was enhanced by 42% and the interfacial strength by 33.7%.

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From a third world country in the 1960s, Singapore managed to achieve first world status by 2010s within a generation. With the rapid rise in urbanization and economic development, the amount of waste generated by the country had also increased from 1200 tons per person per year in the 1970s to 7200 tons per person per year in 2012. This represented a 2-fold increase in waste generated every decade. In order to keep up with the economic development of Singapore, the Singapore Government understand the need to create a sustainable and efficient Solid-Waste Management (SWM) system for the country. This paper examines the SWM system in Singapore as a Large Scale Engineering System where the goals, stakeholders, boundaries and, complexity were examined. Strategies and alternatives were then proposed to improve the system.