2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/225084We give examples of modeling the string free energy whose behavior mimics that of QCD: a power-law at high temperature and an exponential decrease at low temperature. Although the effective description is in terms of strings, no limiting temperature exists, as expected for a crossover.7 pages; v3: discussion improved in section 2, figure and references addedHigh Energy Physics - TheoryHigh Energy Physics - PhenomenologyNuclear Theorytext