2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70182We prove that for smooth projective threefolds whose anticanonical divisors are nef, the second Chern classes are pseudo-effective under a weak assumption. As an application, the pseudo-effectivity of the second Chern classes implies that Kawamata's Effective Non-vanishing Conjecture holds for such threefolds.18 pagesAlgebraic Geometry14C17; 14E30; 14J30text