No abstract

The aerospace industry mostly uses the aluminum alloys 2xxx and 7xxx series for their fuselage construction, and some of them are assembled using structural bonding because it is strong, easy during the fabrication process, resistant to corrosion, and non-toxic. The anodization process is a proven surface treatment method for structural bonding. Phosphoric Sulfuric Acid Anodizing (PSA) is an eco-friendly alternative as a chromate-free solvent technology for the anodizing process that is applied for structural bonding. The thickness of the oxide layer caused by the voltage given in this process was evaluated in terms of corrosion resistance using the oxide layer's thickness as the main factor. The PSA process of AA2024 T3 clad was carried out at a constant concentration of 125 g/L of phosphoric acid, 80 g/L of sulfuric acid, 27 A, and a temperature of 26 to 28 OC for 23 minutes with various voltages. The voltage was varied at 16, 18, and 20 VDC. The optimum condition for the voltage applied was 18 VDC, which resulted in an oxide layer thickness of 2.76 µm.

Vetiver plant is a plant that can be used as essential oil, phytoremediation, Au extraction. This research on vetiver plants was carried out with the aim of finding the highest percentage of the increase in yield density of vetiver plant extracts. The research was carried out at the Bandung State Polytechnic Process Unit Laboratory. The raw materials used come from the city of Garut, West Java, and the sizes are uniformed by 0.5 cm and 1.5 cm. This research was conducted with a ratio of raw material of vetiver and solvent of 1 : 10 (w/v). The solvent used is n-hexane. The operating condition used is an operating temperature of 70⁰C. The time used depends on the length of the cycle required for the operation process. The test method is density measurement using a pycnometer. The temperature used for testing is room temperature 25⁰C – 27⁰C. A number of extract samples were put into a picnometer and weighed using an analytical balance. Based on the results obtained from these conditions, it can be seen that there was an increase in the extract percentage from 0.031% in cycle 1 to 0.975% in cycle 9 at a particle size of 0.5 cm. While the results obtained at a size of 1.5 cm were 0.063% extract in cycle 1 and 1.111% in cycle 9. The highest extract percentage was obtained at a sample size of 0.5 cm in the 9th cycle.