Transesterification of Kapok (Ceiba pentandra) Oil Using Sonication Rizki Putra Samudra, Bambang Susilo, La Choviya Hawa and Wafa Nida Faida Azra BIO Web Conf., 123 (2024) 04008 Published online: 30 August 2024 DOI: 10.1051/bioconf/202412304008