Nonequilibrium transport equations and ab initio study of adsorption processes on carbon nanotubes

In a theoretical study of gas adsorption on carbon nanotubes (CNT) nonequilibrium processes of ionization, polarization, surface diffusion and desorption of atoms are considered self-consistently. The approach is based on Zubarev's method of nonequilibrium statistical operator and reaction-diffusion theory. The set of nonlinear transport equations are obtained for the chosen parameters of description: the average numbers of adsorbed atoms, ionized and polarized atoms in the electromagnetic field of CNT, and the average number of atoms desorbed from the CNT surface. Ab initio simulations are conducted for a "gas-single wall carbon nanotube" system for gases of particular practical interest: He and NO. The obtained values of adsorption energy reveal preferable localization sites of absorbed He atoms as well as their dependency on adsorption distances. A significant effect of NO adsorption on CNT electronic properties is demonstrated. The effect of presence of vacancies on adsorption nature is analyzed. It is shown that under the influence of vacancy formation the CNT structure undergoes reconstruction that enables chemisorption of NO molecules.Comment: 12 pages, 4 figure

A facility and a web application for real-time monitoring of the TTC backbone status

The Timing Trigger and Control (TTC) system distributes timing signals from the LHC Radio Frequency (RF) source to the four experiments (ATLAS, ALICE, CMS and LHCb). A copy of these signals is also transmitted to a monitoring system, installed in the CERN Control Centre, which provides continuous measurement of selected parameters. A web application has been designed to ensure real time remote monitoring and post-mortem analysis of these data. The implemented system is aimed at providing a tool for a fast detection of TTC signal abnormality and unavailability which results in reliability improvement of the whole TTC dependent infrastructure. The paper discusses the architecture of the monitoring system including measurement setup as well as various concerns of data acquisition, storage and visualization

New records of lichens and allied fungi from the Leningrad Region, Russia

Twelve species of lichenized and two lichenicolous fungi, and one non-lichenized calicioid fungus are reported from the Leningrad Region (Eastern, Western or Saint-Petersburg). Lecanora norvegica and Opegrapha lamyi are reported for the first time for Russia. Six taxa are also new to the whole Leningrad Region; four, Lecidella flavosorediata, Ochrolechia bahusiensis, Phaeocalicium praecedens and Tremella lichenicola – to North-Western European Russia, and one, the anamorphic lichen Dictyocatenulata alba is new to European Russia. Brief discussions on the species are included.

New records of lichens and allied fungi from the Leningrad Region, Russia. III

Eight species of lichen-forming, eight lichenicolous and three non-lichenized fungi are reported from the Leningrad Region. Arthonia caerulescens, A. ligniaria, Hawksworthiana peltigericola, Micarea pycnidiophora and Trichonectria rubefaciens are new to Russia; Micarea lutulata, Protoparmelia oleagina and Stictis radiata are new to the North-Western European Russia; Lichenoconium lecanorae, Phaeocalicium populneum, Phaeosporobolus usneae, Ramboldia cinnabarina, Stictis brunnescens and Strigula stigmatella are new to the Leningrad Region. Most noteworthy records are briefly discussed.

New records of lichens and allied fungi from the Leningrad Region, Russia. V

Eight species of lichens and seven lichenicolous fungi are reported from the Leningrad Region. Agonimia repleta, Protoparmelia hypotremella and Stereocaulon taeniarum are reported for the first time for Russia; Clypeococcum cetrariae is new to the European Russia; Lepraria nivalis, Merismatium aff. nigritellum (on Physcia aipolia) and Stigmidium leprariae are new to the North-Western European Russia; Cladonia macroceras, C. strepsilis, Endococcus fusiger, Lichenoconium erodens, Lobothallia melanaspis, Niesslia cladoniicola and Skyttella mulleri are new to the Leningrad Region; Sclerophora coniophaea is new to Saint Petersburg. The most noteworthy records are briefly discussed.

Konevets Island (Leningrad Region, Russia) – a historical refuge of lichen diversity in Lake Ladoga

We present an updated checklist for Konevets Island (Leningrad Region, Russia). The revealed lichen biota comprises 435 species, including 378 lichens, 46 lichenicolous fungi and 11 non-lichenized saprobic fungi, of which 31 species (27 lichens and 4 lichenicolous fungi) are known only from collections made by Veli Räsänen (1917, 1938). Acremonium hypholomatis is reported for the first time for Russia; Caloplaca soralifera, Trapelia corticola, and Muellerella lichenicola for Northwestern European Russia; and Bacidia vermifera, Lecanora mughicola, Micarea contexta, Pyrenochaeta xanthoriae, Rhizocarpon disporum, Stigmidium squamariae and Xylographa difformis for Leningrad Region. From lichenological point of view, the most valuable habitats of Konevets Island are old-growth spruce forests. The studied lichen biota is rich and diverse and exceptionally well-preserved in comparison to the mainland part of Karelian Isthmus. It definitely deserves protection

New records of lichens and allied fungi from the Leningrad Region, Russia. IX.

Eight species of lichens and seven lichenicolous fungi are reported for the first time for St. Petersburg, the whole Leningrad Region or its western or eastern parts. The lichen Xylographa septentrionalis is reported for the first time for Russia, Europe and Asia, the lichenicolous fungus Skyttea gregaria is new for Russia, the lichen Xylographa pallens, lichenicolous fungi Didymellopsis collematum and Intralichen lichenicola are new for the North-Western European Russia. The most interesting records are briefly discussed.Peer reviewe

New records of lichens and allied fungi from the Leningrad Region, Russia. VIII

Thirteen species and one variety of lichens, nine lichenicolous and two saprobic fungi are reported for the first time for St. Petersburg, the whole Leningrad Region or its western or eastern parts. The lichens Bacidina brandii, B. neosquamulosa, Porina leptalea, Rinodina aspersa and the lichenicolous fungus Scutula dedicata are reported for the first time for Russia, lichenicolous fungus Lichenoconium aeruginosum – for European Russia, the lichen Tetramelas chloroleucus, lichenicolous fungi Lichenoconium pyxidatae and Tremella cetrariicola are new for the North-Western European Russia. The most interesting records are briefly discussed.

UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications