2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/119054We study quarks moving in strongly-coupled plasmas that have supergravity duals. We compute the friction coefficient of strings dual to such quarks for general static supergravity backgrounds near the horizon. Our results also show that a previous conjecture on the bound has to be modified and higher friction coefficients can be achieved.9 pages, harvmac (b)High Energy Physics - Theorytext