The increasing demand for vehicles is resulting in environmental problems, such as a higher demand for fossil fuels and higher CO2 emissions. Lightweight materials, such as fiberreinforced polymers, have been used in automotive components to reduce the weight, fuel consumption, and CO2 emissions of vehicles. Natural fibers are often used as substitutes for glass fibers because they are abundant and require less energy to produce compared to glass fibers. The present research focused on the preparation and characterization of composites reinforced with Sansevieria trifasciata fiber (STF). High-impact polypropylene (HIPP) and vinyl ester (VE) were chosen and compared as matrix materials. The results showed that the mechanical properties of the produced biocomposites increased with increasing amounts of fiber, alkaline treatment, and unidirectional fiber orientation. A tensile strength of 59.77 MPa and a stiffness of 1.97 GPa were obtained for STF/HIPP composites with unidirectional alkali treatment and a 15% volume fraction of fiber. Moreover, a tensile strength of 121.1 MPa and a stiffness of 7.65 GPa were obtained for STF/VE composites with unidirectional alkali treatment and a 15% volume fraction of fiber. The STF/VE biocomposites were comparable to commercial glass fiber composites for automotive applications and even exhibited greater tensile strength properties.

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Sudu turbin merupakan komponen dari mesin pesawat yang akan terekspose pada temperatur tinggi. Material superalloys banyak digunakan sebagai bahan untuk membuat sudu turbin, karena memiliki kekuatan yang baik pada temperatur tinggi. Salah satu material superalloy yang digunakan adalah SRR 99, yang merupakan material nickel based superalloys yang memiliki butir tunggal. Namun, material ini juga akan mengalami perubahan struktur mikro dan sifat mekanik pada saat terekspose pada temperatur yang terlalu tinggi. Penelitian ini mempelajari pengaruh pemanasan diatas temperatur kerja atau temperatur overheat terhadap struktur mikro dan sifat mekanik dari material sudu turbin Nickel Based Superalloys SRR 99. Temperatur pemanasan yang digunakan sebesar 1250oC. Dari hasil pemanasan yang dilakukan terjadi penurunan ukuran partikel γ’ sebesar 51% dan kenaikan harga kekerasan dari kekerasan awal sebesar 13% dibandingkan dengan kondisi sebelum pemanasan. Sedangkan variasi waktu yang dilakukan pada penelitian ini tidak memberikan perbedaan yang signifikan terhadap perubahan ukuran partikel γ’ dan nilai kekerasan.Kata kunci: sudu turbin, mikrostruktur, nickel based superalloys, SRR 99

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Top of line (TOL) corrosion is a common corrosion case found on pipe that flows wet gas in oil and gas industry. The present study aims to evaluate the impact of mono ethylene glycol (MEG) on the TOL corrosion rate of low carbon steel in acidic environment with increased temperature. The study was conducted at temperature 50 °C and 70 °C in a solution containing 2000 ppm of acetic acid and 50 % volume of MEG. There are four types of experimental conditions with variation in the temperature and MEG content were used. The result present that MEG effectively reduce the condensation rate and TOL corrosion rate of low carbon steel at elevated temperature environment. This revealed that increasing of TOL corrosion inhibition effect along the experimental period. Moreover, the increased level of severity was associated with increased temperature. The results concluded that this procedure resulted due to decrease in condensation rate that is likely to reduce the supply of electrolyte for the corrosion reaction.