Ramp temperature and Dufour effects on transient MHD natural convection flow past an infinite vertical plate in a porous mediumNarahari Marneni, Sowmya Tippa and Rajashekhar PendyalaEur. Phys. J. Plus, 130 12 (2015) 251DOI: https://doi.org/10.1140/epjp/i2015-15251-9