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PublicationInvestigation of Empennage Location Effect to the Unmanned Aerial Vehicle (UAV) Structure Characteristic( 2024)Over the past few decades, unmanned aerial vehicles, commonly known as UAVs, have been widely used in a number of consumer and military applications, such as surveillance, tracking, monitoring, and aerial photography. Fixed-wing and rotary UAVs are the two primary categories in UAV. Interestingly, the hybridization of fixed-wing and rotary UAV gives better performance in terms of energy consumption and the needs of runaway. Designing new hybrid fixed wing-rotary UAV or hybrid vertical take-off and landing (VTOL) is challenging especially to identify the critical location in the UAV and material selection. Therefore, the objective of this research is to study the effect of empennage location and material selection on the structural strength of a hybrid VTOL UAV. The SolidWorks software was employed to design a 3D model of the UAV with different empennage locations, as well as perform a simulation of the structural strength of fibre glass, carbon fibre and kenaf for the hybrid VTOL UAV. The simulation analysis presents stress (Von Mises). The results show that the fibre glass (4.342 N/m2) at top empennage gives the best performance as compared to other parameters. In conclusion, this study is necessary to give a better picture of structural strength of composite materials and best design location in hybrid VTOL UAV for future research.
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PublicationElucidation on alkali activation of slag with various solid-to-liquid ratios via heat evolution( 2024)This research intends to evaluate alkali activation of slag through heat evolution for emphasizing the potential of ambient curing. The heat evolution and cumulative heat evolved acquired were used to further investigate the nucleation and growth mechanisms by using the Johnson Mehl Avrami Kolmogrov model. Increasing the solid-to-liquid ratio resulted in significant changes to the peaks intensity of heat evolution and a decrease in total cumulative heat evolved. Meanwhile, it was found that the nucleation mechanism and growth is driven by instantaneous heterogeneous nucleation with rod-like growth. Furthermore, the lowest heat evolved (238.72 J/g) with the highest growth rate was discovered to produce superior compressive strength properties (51.667 MPa) as well as densified morphology and fewer in microcracks creation compared to the highest total heat evolved (346.92 J/g). The elemental distribution of alkali-activated slag with the least cumulative heat evolved also demonstrated a homogeneous distribution of important elements including silicon, aluminum, and calcium following alkali activation.
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PublicationFly ash porous material using geopolymerization process for high temperature exposure( 2012)This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.
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