Fig. 1. (a) Thermal mechanical analysis (TMA) scan of Harpeth humic acid (HHA), noting initial thermal transition (T₁) near 21°C, and second transition (T₂) at 43°C; (b) TMA scan of Harpeth fulvic acid (HFA), noting initial transition (T₁) near –7°C, second transition (T₂) near 30°C, and third transition (T₃) near 54°C; (c) TMA scan of Georgetown humic acid (GHA) and Georgetown fulvic acid (GFA) indicating a transition near 21 and 17°C, respectively; (d) TMA scan of Harpeth carbohydrate (HCH) indicating transitions near –23 and 22°C.