Phrynopus AmphibiaWeb keeps "Noblella" in Strabomantidae/Strabomantinae, a family/subfamily no longer recognized by the Amphibian Species of the World. "Phrynopus" are small to medium-sized frogs, from snout–vent length in "Phrynopus auriculatus" to in "Phrynopus kauneorum". Head is narrower than the body. Differentiated tympanic membrane and tympanic annulus are usually absent, except in "Phrynopus auriculatus" and "Phrynopus peruanus", two basal species. Dorsum is smooth to pustulate. Venter is smooth or areolate. There are 26 species in this genus: Phrynopus Phrynopus is a genus of frogs of the Craugastoridae family. Their common name is Andes frogs. They are endemic to Peru and inhabit the
Membrane technology in the fluid and membrane phases can be equated at the solution-membrane interface. This principle is more important for "dense" membranes without natural pores such as those used for reverse osmosis and in fuel cells. During the filtration process a boundary layer forms on the membrane. This concentration gradient is created by molecules which cannot pass through the membrane. The effect is referred as concentration polarization and, occurring during the filtration, leads to a reduced trans-membrane flow (flux). Concentration polarization is, in principle, reversible by cleaning the membrane which results in the initial flux being almost totally restored. Using a