Excursions into the Evolution of Early-Type Galaxies in Clusters

Recent observations have revealed that early-type galaxies (ETG) in clusters comprise an old galaxy population that is evolving passively. We review some recent observations from the ground and from HST that show that ETG have undergone a significant amount of luminosity evolution. This evolution is traced by two projections of the fundamental plane (FP): the size-magnitude relation (SMR) and the color-magnitude relation (CMR). We will briefly discuss the relevance of all these results in the context of the universality of the IMF.Comment: 10 pages, 2 figures, to appear in the proccedings of "New Quests in Stellar Astrophysics: The Link Between Stars and Cosmology, Chavez et al. ed

Mathematical Solution of the Problem of Roll Waves in Inclined Open Channels

the nondimensional wavespeed as a function of the rotational Froude number. For the same Froude number, the rotational wavespeed is slightly greater than the equivalent inclined film wavespeed. A stability condition for wave motion has also been obtained. The stability condition indicates that the critical Froude number for rotating films is larger than that for inclined films