Study of Mathematical Models in Hot Air Drying of Herbs in Herbal Compress Ball Boochita Wongpanit, Sumitta Chotikamas, Supacharee Roddecha, Prapakorn Tantayotai and Malinee Sriariyanun MATEC Web Conf., 187 (2018) 01002 Published online: 06 August 2018 DOI: 10.1051/matecconf/201818701002