Zanin R.,Intitut de Fisica dAltes Energies |
Mazin D.,Intitut de Fisica dAltes Energies |
Colin P.,Max Planck Institute |
Cortina J.,Intitut de Fisica dAltes Energies |
And 6 more authors.
Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011 | Year: 2011
The Crab Pulsar Wind Nebula is the best studied source of γ-ray astrophysics. The contribution of the various soft radiation fields to the Inverse Compton component of its high energy emission, the strenght of the internal magnetic field and the maximum energies reached by primary electrons are however still matter of study. The MAGIC stereoscopic system recorded almost 50 hours of Crab Nebula data in the last two years, between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereo software provided an unprecedented differential energy spectrum spanning three decades in energy, from 50 GeV up to 45 TeV. At low energies, the MAGIC results, combined with the Fermi/LAT data, yield a precise measurement of the Inverse Compton peak. In addition, we present light curves of the Crab Nebula at different time scales, including a measurement simultaneous to one of the Crab Nebula flares recently detected by both Fermi/LAT and AGILE. Using the MAGIC spectrum together with multiwavelength data, we discuss the implications for the modeling of the Crab Nebula.
Rudolf B.,University of odz |
Salmain M.,École Nationale Supérieure de Chimie de Paris |
Haquette P.,École Nationale Supérieure de Chimie de Paris |
Stachowicz M.,University of Warsaw |
Wozniak K.,University of Warsaw
Applied Organometallic Chemistry | Year: 2010
Owing to their unique properties, ferrocene compounds are gaining increasing interest for biological applications, particularly as enzyme inhibitors. Phosphonate derivatives including a ferrocenyl moiety were synthesized by reaction of dimethyl- and diphenylphosphite with ferrocenyl methyl maleimide. The ferrocenyl diphenyl phosphonate complex was characterized by X-ray diffraction. The ability of these organometallic compounds to inhibit the enzymatic activity of the serine esterases acetyland butyrylcholinesterase was investigated. It appeared that the new ferrocenyl phosphonates inhibited both enzymes by competitive, mixed or non competitve mechanisms with inhibition constants in the range 35-1000 μM. Both compounds also behave as slow time-dependent inactivators of butyrylcholinesterase. The presence of the ferrocenyl entity seems then to have a dramatic effect on the biochemical behavior of the systems. Copyright © 2010 John Wiley & Sons, Ltd.
Mloston G.,University of odz |
Roza H.-F.,University of odz |
Linden A.,University of Zürich |
Heimgartner H.,University of Zürich
Beilstein Journal of Organic Chemistry | Year: 2016
Ferrocenyl hetaryl thioketones react smoothly with in situ generated thiocarbonyl S-methanides to give 1,3-dithiolanes. In the case of aromatic S-methanides, the sterically more crowded 4,4,5,5-tetrasubstituted 1,3-dithiolanes (2-CH2 isomers) were formed as sole products. The reactions with cycloaliphatic S-methanides led to mixtures of 2-CH2 and 5-CH2 isomers with the major component being the sterically more crowded 2-CH2 isomers. The preferred formation of the latter products is explained by the assumption that the formal [3 + 2]-cycloadducts were formed via a stepwise reaction mechanism with a stabilized 1,5-diradical as a key intermediate. The complete change of the reaction mechanism toward the concerted [3 + 2]-cycloaddition was observed in the reaction of a sterically crowded cycloaliphatic thiocarbonyl ylide with ferrocenyl methyl thioketone. © 2016 Mlostoñ et al.;.
Degirmendzic J.,University of odz |
Kozuchowski K.,Branch of the University of odz in Tomaszow Mazowiecki
Quaestiones Geographicae | Year: 2015
The article presents the results of the analysis of precipitation in Poland associated with cyclones moving from the Mediterranean Sea to East-Central Europe (Mediterranean Cyclonal Precipitation - MCP). The MCP accounts for about 10% of the total amount of precipitation in Poland. Average daily sum of MCP constitutes approximately 150% of daily amount of all precipitation in Poland. The MCP amount reaches its maxima at the end of April and in the mid-August. The highest MCP occurs in the Carpathians and the Sudetes as well as over stripes of land extending northward and covering the central-western and eastern parts of the country. In the years 1958-2008, the mean annual MCP was characterized by a significant decreasing trend - the MCP sum reduced by 29 mm, i.e. ca. 42% of its multiannual value. © 2015 Faculty of Geographical and Geological Sciences, Adam Mickiewicz University.
Szaowski K.,University of Odz |
Balcerzak T.,University of Odz |
Bobak A.,University of P.J. Šafarik
Journal of Magnetism and Magnetic Materials | Year: 2011
The thermodynamics of a site-diluted ferromagnetic Heisenberg model for spin S=1/2 with interaction anisotropy in spin space is investigated. The study is aimed at presenting the magnetocaloric properties of such a model, including the entropy and temperature changes in magnetization/demagnetization processes, generalized Grüneisen ratio as well as the quantities characterizing the efficiency of magnetic cooling cycles. The results are obtained using pair approximation (PA) method and extensively compared with the molecular field approximation (MFA) calculations. The importance of interaction anisotropy and site-dilution is discussed. The inadequacy of the MFA approach (even on the qualitative level) is found for selected quantities, while PA provides the results which are consistent with the experimentally observed behavior. © 2011 Elsevier B.V. All rights reserved.
Szalowski K.,University of odz
Acta Physica Polonica A | Year: 2014
The indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling between on-site magnetic impurities is studied for two kinds of graphene nanoflakes consisting of approximately 100 carbon atoms, posessing either zigzag or armchair edge. The tight-binding Hamiltonian with Hubbard term is used in non-perturbative calculations of coupling between the impurities, placed at the edge of the structure. In general, for zigzag-edged nanoflakes a pronounced coupling robust against charge doping is found, while for armchair-edged structures the interaction is weaker and much more sensitive to charge doping. Also the distance dependence of indirect exchange differs significantly for both edge forms.
Rakowska B.,University of odz
Diatom Research | Year: 2010
Live specimens of Fallacia helensis (Schulz) D.G. Mann were recorded in the silt of a plant settling tank that purifies water (ground and surface) drained from a brown coal mine. In Poland the species had previously been identified only in fossil material from the Pleistocene and Holocene (Marciniak 1973, Marciniak & Przybylowska-Lange 1977). Morphometric data and an ecological analysis, including data on associated diatom species, are presented.