2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/151701We briefly introduce tweed, which is found above the martensitic transition in a variety of shape-memory, high-T_c, and other materials. Based on our previous mapping of the problem onto a spin-glass model, we conjecture that the two-way shape-memory effect is due to tweed.Originally presented at Los Alamos in April, 1995Disordered Systems and Neural NetworksMaterials ScienceStatistical Mechanicstext