Vittarioideae worthy of subgeneric rank, while "Rheopteris" had not yet been discovered. "Haplopteris" he explicitly synonymized with "Vittaria" in 1914. Carl Christensen used the name "Vittarioideae" in Verdoorn's "Manual of Pteridology" in 1938, but did not include a description, leaving it nomenclaturally invalid. Ren-Chang Ching raised Vittariaceae to the rank of a family in 1940. The first well-sampled molecular phylogenetic study of the vittarioids was based on the chloroplast gene rbcL. In this study, it was found that the type species of "Monogramma" is embedded in "Haplopteris"; the segregation of "Vaginularia" from "Monogramma" was also supported, as members of "Vaginularia" formed
Economics of nuclear power plants due to the large sunk costs but unpredictable future income from the liberalized electricity market, private capital is unlikely to be available on favourable terms, which is particularly significant for nuclear as it is capital-intensive. Industry consensus is that a 5% discount rate is appropriate for plants operating in a regulated utility environment where revenues are guaranteed by captive markets, and 10% discount rate is appropriate for a competitive deregulated or merchant plant environment; however the independent MIT study (2003) which used a more sophisticated finance model distinguishing equity and debt capital had a higher 11.5% average discount rate. As