Khairiyah, Aisyah Nurul, Gandi Sugandi, and Deddy Kurniadi. 2023. “Design and Characterization of Ultrasonic Langevin Transducer 20 KHz Using a Stepped Horn Front-Mass”. Journal of Engineering and Technological Sciences 55 (4):357-72. https://doi.org/10.5614/j.eng.technol.sci.2023.55.4.1.