Hydrophobic-Hydrophilic Solvation of Variously Substituted N-Alkylureas in Aqueous Solution: A Calorimetric Study at a Temperature of 298.15 K Della Gatta, G.; Badea, E.; Jóźwiak, M.; Barone, G.; Journal of Chemical & Engineering Data 2009, 54, 2739-2744