The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

Twenty-three species of crustose Teloschistaceae were collected from the northwest of the Murmansk region of Russia during field trips in 2013 and 2015. Blastenia scabrosa is a new combination supported by molecular data. Blastenia scabrosa, Caloplaca fuscorufa and Flavoplaca havaasii are new to Russia. Blastenia scabrosa is also new to the Caucasus Mts and Sweden. Detailed morphological measurements of the Russian specimens of these species are provided. Caloplaca exsecuta, C. grimmiae and C. sorocarpa are new to the Murmansk region. The taxonomic position of C. alcarum is briefly discussed.