58 research outputs found

    Lichens of the Innvika Bay, Prins Oscars Land (Nordaustlandet, Svalbard)

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    The paper presents a list of lichens for the Innvika Bay, which includes 157 lichenized and 2 lichenicolous fungi. Alectoria gowardii and Peltigera elisabethae are new to Svalbard. Furthermore, 36 other species were found new to Nordaustlandet. Twenty-seven species are rare on Svalbard, among them Aspilidea myrinii, Candelariella borealis, Gyalecta erythrozona, Miriquidica deusta, Rhizocarpon viridiatrum (reported for the second time), and Aspicilia cinerea, Cetraria nigricans, Cladonia arbuscula, Cystocoleus ebeneus, Lecidea ecrustacea, Peltigera frippii, Rhizocarpon eupetraeoides, Rinodina terrestris, Stereocaulon cumulatum, Toninia squalida, Verrucaria hydrela. Localities, substrates and distribution in Svalbard are given for each species. For rare and extremely rare species, all known locations are given. For some species, differences from closely related species are given

    Spilling breakers : applications to Favre waves and to the shoaling and the breaking of the solitary wave

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    A two-layer long wave approximation of the homogeneous Euler equations for a free surface flow over a rigid bottom is derived. The upper layer is turbulent and is described by depth averaged equations for the layer thickness, the average fluid velocity inside the layer, and the fluid turbulent energy. The lower layer is almost potential and can be described by Serre–Su–Gardner–Green–Naghdi equations (second order shallow water approximation with respect to the parameter H/L where H is a characteristic water depth, and L is a characteristic wave length). The interaction between the layers is due to the turbulent mixing. The dynamics of the interface separating two layers is governed by the turbulent energy of the upper layer. Stationary supercritical solutions to this model are first constructed , containing, in particular, a local subcritical zone at the forward slope of the wave. Such a local subcritical zone corresponds to an intense increasing of a turbulent layer thickness and can thus be associated with the spilling breaker formation. Non-stationary model was then numerically solved and compared with experimental data for the following two problems. The first one is the study of surface waves resulting from the interaction of a uniform free surface fluid flow with an immobile wall ('the water hammer problem with a free surface'). These waves are sometimes called 'Favre waves' in homage to Henry Favre and his contribution to the study of this phenomena. When the Froude number is between 1 and approximately 1.3, the undular bore appears. The turbulent energy of the flow is localized at the wave crests. The characteristics of the leading wave are in good agreement with the experimental data by Favre (1935) and Treske (1994). When the Froude number is between 1:3 and 1:4, the transition from the undular bore to the breaking (monotone) bore occurs. In the breaking bore, the turbulent energy is localized at the front of the bore. The shoaling and the breaking of the solitary wave propagating in a mild - slope (1/60) long channel (300 m) was then studied. Comparisonwith the experimental data by Hsiao et.al. (2008) show a very good agreement of the wave profile evolution

    Lichens and allied fungi from the Pechenga district and surroundings (Lapponia Petsamoënsis, Murmansk Region, Russia)

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    168 species of lichens are specified for the Pechenga district and surroundings. Microcalicium ahlneri and Placidium norvegicum are new for the Murmansk Region. 18 species are new for Lapponia Petsamoënsis. Stereocaulon dactylophyllum is included into the Red Data Book of the Russian Federation. Caloplaca diphyodes, Dermatocarpon meiophyllizum, Haematomma ochroleucum, Phlyctis argena and Stereocaulon dactylophyllum are included into the Red Data Book of the Murmansk Region

    Addition to the lichen biota of Franz Josef Land archipelago

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    Forty-four new lichen species and one lichenicolous fungus have been identified as a result of studies of the lichen biota of the Franz Josef Land archipelago. Bryocaulon hyperboreum was reported for the first time from Russia. Gyalecta hypoleuca and Umbilicaria maculata were first identified in the Arctic. Arctocetraria andrejevii, Brodoa oroarctica, Candelariella borealis, Cercidospora stereocaulorum, Massalongia carnosa, Miriquidica nigroleprosa, M. plumbeoatra, Myriolecis zosterae var. palanderi and Polyblastia gothica are new to the Arkhangelsk Region; and Arthrorhaphis citrinella, Mycoblastus alpinus, Racodium rupestre, Rhizocarpon ferax, Scytinium intermedium, Stereocaulon glareosum are new to the Arctic part of the Arkhangelsk Region. Species new to Arkhangelsk Region, Arctic and Russia are supplied with information on distribution in neighboring regions and world and on differences from closely related species. The checklist of the Franz Josef Land archipelago thus includes 277 species and 6 varieties of lichenized and 43 lichenicolous fungi to date

    Lichens and vascular plants in Duvefjorden area on Nordaustlandet, Svalbard

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    Floristic check-lists were compiled for the first time for Duvefjorden Bay on Nordaustlandet, Svalbard, based on field work in July 2012 and on data from literature and herbaria. The check-lists include 172 species of lichens and 51 species of vascular plants. Several species rare in Svalbard and in the Arctic were discovered: Candelariella borealis was new to Svalbard. 51 lichen species were newly recorded on Nordaustlandet and 131 lichen species were observed in the Duvefjorden area for the first time. Among lichen species rare in Svalbard and in the Arctic the following can be mentioned: Caloplaca magni-filii, C. nivalis, Lecidea silacea, Phaeophyscia nigricans, Polyblastia gothica, Protothelenella sphinctrinoidella, Rinodina conradii, Stenia geophana, and Tetramelas pulverulentus. Two species of vascular plants, Saxifraga svalbardensis and S. hyperborea, were found new to the Duvefjorden area. The investigated flora is represented mostly by species widespread in Svalbard and in the Arctic. Although Duvefjorden area is situated in the northernmost part of Svalbard, its flora is characterized by relatively high diversity of vascular plants and lichens. Apparently this is due to the influence of the warm North Atlantic Current

    First Principle Evaluation of Photocatalytic Suitability for TiO2-Based Nanotubes

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    Water splitting under the influence of solar light on semiconducting electrodes Immersed in aqueous electrolyte is a potentially clean and renewable source for hydrogen fuel production. Its efficiency depends on relative position of the band gap edges (the visible light interval between infrared and ultraviolet (UV) ranges of electromagnetic spectrum corresponds to gap widths 1.5–2.8 eV) accompanied by a proper band alignment relative to both reduction (H+/H2) and oxidation (O2/H2O) potentials (−4.44 eV and −5.67 eV on energy scale for vacuum, respectively) which must be positioned inside the band gap. Its width for TiO2 anatase-structured bulk is experimentally found to be 3.2 eV, which corresponds to photocatalytic activity under UV light possessing only ~1% efficiency of sunlight energy conversion. Noticeable growth of this efficiency can be achieved by by adjusting the band gap edges for titania bulk through nanoscale transformation of its morphology to anatase-type nanotubes (NTs) (formed by folding of (001) or (101) nanothin TiO2 sheets consisting of 9 or 6 atomic layers and possessing either (n,0) or (−n,n) chiralities, respectively) accompanied by partial substitution of pristine atoms by CO, FeTi, NO and SO single dopants as well as NO+SO codopants. In the latter case, the band gap can be reduced down to 2.2 eV while the efficiency is achieved up to ~15%. The energy differences between the edges of band gap (VB and CB), the highest occupied and lowest unoccupied impurity levels inside the band gap (HOIL and LUIL, respectively) induced in doped NTs, while preserving the proper disposition of these levels relatively to the redox potentials, so that εVB<εHOIL<εO2/H2O<εH+/H2<εLUIL<εCB, thus reducing the photon energy required for dissociation of H2O molecule. In this chapter, we analyze applicability of large-scale first principle calculations on the doped single-wall titania NTs of different morphologies with the aim of establishment of their suitability for photocatalytic water splitting

    The lichens of the northern shore of the Gulf of Finland in the limits of St. Petersburg, Russia – diversity on the edge of the megapolis

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    We present a lichen checklist for the northern shore of the Gulf of Finland in the limits of St. Petersburg, Russia. This area has diverse lichen biota within the city limits, and has been comprehensively studied since 1893, which gives a good base for analysis of historical changes in lichen diversity. The documented lichen biota comprises 469 species (430 lichenized, 24 lichenicolous, 3 facultatively lichenicolous, and 12 non-lichenized saprobic fungi), of them 191 species are known from herbaria and literature for the period before 1991, and 436 species were recorded since 1991 to 2019. Thirty-three taxa were excluded from the lichen list of the study area as erroneous or dubious records. Altogether 48 species are new to St. Petersburg, including: Lecidea malmeana and Micarea czarnotae – new to Russia; Caloplaca lucifuga, Gyalecta nigricans, Micarea soralifera – new to European Russia; Agonimia flabelliformis, Endococcus verrucosus, Lecania turicensis, Micarea fallax, M. tomentosa, Xanthomendoza huculica – new to Northwestern European Russia; Lichenoconium lichenicola, Ramalina europaea, Sarcogyne hypophaea – not known also from the Leningrad Region. The studied lichen biota is moderately rich compared to other city territories. The history of economic development of the region has caused its serious transformation, degradation of natural habitats and therefore partial loss of lichen diversity. At the same time, human-made substrates and anthropogenic plant communities are inhabited by lichens, including species unknown in the natural habitats of the study area. However, 44 species recorded in the study area are red-listed in St. Petersburg, with 13 of them known only from historical collections. Forest communities, as well as historical parks, in NW part of St. Petersburg are important source of biodiversity on regional level nowadays and hopefully in future, and deserve protection

    The lichens of Pukhtolova Gora (St. Petersburg, Russia)

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    The lichen diversity of the proposed protected area Pukhtolova Gora counts 252 species, including 232 lichenized, 12 lichenicolous, and 8 non-lichenized saprobic fungi. Micarea laeta, M. pusilla, and Pyrenidium actinellum s. lat. are new to North-Western European Russia; Parmelia serrana, Rhizocarpon cinereovirens, and Stereocaulon taeniarum are new to St. Petersburg. Altogether 13 species recorded in the study area are red-listed in St. Petersburg, with two of them known only from historical collections. Pukhtolova Gora is an area with a high conservation value; the lichen biota of this area is one of the richest within the city limits due to the well-preserved forest habitats

    Research to Develop a Promising Technology for the Joint Disposal of Man-made Wastes

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    The main components of RM are: Fe (35.7 %) in the form of hematite and complex hydroalumination, Ca (11.0 %) in the form of calcite and hydro-aluminosilicates, Al (6.8 %) and Si (4.7 %) in the composition of hydroalumination, Na (2.8 %) in the form of hydroalumination, carbonate and hydroxide, Ti (2.5 %) in the form of rutile. The main components of the OMS are: Fe (71 %) in the form of magnetite, wustite and hematite with a very small amount of fayalite. The contents of Si (in the form of quartz), Al and P (non-forming phases) are within 1–3 %. Granulometric composition of RM is characterized by high dispersion. With an average diameter of 1.6 μm, all particle sizes are in the range of 0.5–12 μm. Granulometric composition of OMS is characterized by complexity. With an average diameter of 8.6 μm, maxima of 0.9 μm and 15 μm and a minimum of about 1.2 μm are observed in the particle size distribution. The specific surface area of the materials is equal to RM 23.7 m2/g, and OMS – 1.9 m2/g. The change of waste properties after exposure to aqueous solutions of alkalis and acids neutralizing the effect of organic (OMS) and alkaline (RM) surface compounds was studied. Neutralization of aqueous suspension with HCl solution leads to removal of alkaline film from the surface. As a result of the impact of reagents, there is a decrease in the content of water-soluble components in the processing products. At the same time, the average particle sizes of RM and OMS increase to 2 and 14 μm, respectively, and the specific surface area to 25.7 and 2.3 m2/g. The distribution of particle size of RM is almost constant, and the OMS is approximately 5 and 10 % of the smoothed maximum and minimum in the area of at least 0.5 and 15 μm. Keywords: red mud, oiled mill scale, chemical, phase, granulometric, composition, specific surfac