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The article discusses important factors to consider in selecting pumps for the chemical process industries (CPI). Topics discussed include the importance of understanding the sealing and coupling arrangements of pumps, the structure of centrifugal pumps, and the functions of magnetic coupling which is characterized by torque transmission.

We present a taxonomic revision of the lichenized basidiomycete genus Acantholichen, species of which produce a characteristic blue-gray, microsquamulose thallus with spiny apical hyphal cells known as acanthohyphidia. Since its discovery, the genus was thought to be monospecific, only including the generic type, A. pannarioides. However, a detailed morphological and anatomical study of recently collected specimens from the Galápagos, Costa Rica, Brazil and Colombia, combined with a molecular phylogenetic analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and 28S of the nuc rDNA and RPB2 sequences, revealed a much more diverse and widespread species assemblage. Based on the results of these analyses, we describe five new species in the genus: A. albomarginatus, A. campestris, A. galapagoensis, A. sorediatusand A. variabilis. We also provide an identification key to all species, anatomical and morphological descriptions, photographs and a table comparing main characters of each species.

The article offers the author's insights regarding his experiences as a lichen hunter for 20 years. Topics discussed include the physical characteristics, biological compositions, and mutualism between fungus and alga in lichens. Also mentioned are various species, ecological role, and symbiosis in lichens.

The “species pair” concept obscures both intra- and interspecific relationships and should be abandoned, evolutionarily and taxonomically. Based on our molecular phylogenetic work on the genus Roccellawe are able to show for the first time that sexually and vegetatively dispersed entities in an anticipated “species pair” (Roccella galapagoensis/R. lirellina) actually form several distinct monophyletic genotypes, here interpreted as species in which sexual reproduction has been repeatedly evolved. The species accepted here are based on a phylogenetic hypothesis supported by data from the ITS rDNA region and an unidentified locus possibly related to calmodulin. Altogether 89 sequences from both loci were newly produced and used in phylogenetic analyses. The Roccella galapagoensisaggregate was resolved as monophyletic. The sister group includes Roccella decipiens(sexual) and R. gracilis(asexual). Based on the present data it is equally parsimonious to suggest a sorediate or a fertile ancestor to the Roccella galapagoensisaggregate. The ancestor must have arrived in the Galapagos Islands through long distance dispersal and have included the ability to reproduce both sexually with ascospores and asexually with soredia. Taxonomy, nomenclature and phylogeny are provided for five American Roccellaspecies in the Roccella galapagoensisaggregate with geographical focus on the Galapagos Islands. One species is obligatory sexual, one is obligatory asexual and three species are facultative sexual/asexual. Roccella albidaTehler is newly described. Roccella canariensisis united with R. tinctoria.