2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7418From ISO [Ne V] 14.3/24.3 micron line flux ratios, we find that 10 out of 20 planetary nebulae (PNs) have measured ratios below the low-electron density (N_e) theoretical predicted limit. Such astronomical data serve to provide important tests of atomic data, collision strengths in this case. In principle, well-calibrated measurements of the [Ne V] 14.3/24.3 flux ratio could improve upon the existing atomic data.to be published in "Recycling intergalactic and interstellar matter", IAU Symposium Series, Vol. 217, 2004, P.-A. Duc, J. Braine and E. Brinks, edsAstrophysicsFlux ratio [Ne V] 14.3/24.3 as a test of collision strengthstext