294 research outputs found

    Peculiar Motions in the Region of the Ursa Major Supercluster of Galaxies

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    We have investigated the peculiar motions of clusters of galaxies in the Ursa Major (UMa) supercluster and its neighborhood. Based on SDSS (Sloan Digital Sky Survey) data, we have compiled a sample of early-type galaxies and used their fundamental plane to determine the cluster distances and peculiar velocities. The samples of early-type galaxies in the central regions (within R_200) of 12 UMa clusters of galaxies, in three main subsystems of the supercluster -- the filamentary structures connecting the clusters, and in nine clusters from the nearest UMa neighborhood have similar parameters. The fairly high overdensity (3 by the galaxy number and 15 by the cluster number) suggests that the supercluster as a whole is gravitationally bound, while no significant peculiar motions have been found: the peculiar velocities do not exceed the measurement errors by more than a factor of 1.5-2. The mean random peculiar velocities of clusters and the systematic deviations from the overall Hubble expansion in the supercluster are consistent with theoretical estimates. For the possible approach of the three UMa subsystems to be confirmed, the measurement accuracy must be increased by a factor of 2-3.Comment: 21 pages, 4 tables, 7 figure

    STUDY OF SEISMIC EFFECTS ON CHANGES IN GROUNDWATER PRESSURE: EQUIPMENNT AND SOME WELL OBSERVASTION RESULTS FOR THE KAMCHATKA PENINSULA

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    The relevance of the work is determined by the necessity to develop the hardware part of the seismic subsystem of the Large-Scale Research Facilities functioning at the Federal Research Center of the Geophysical Survey of the Russian Academy of Sciences to study seismic signals in groundwater pressure changes. For this purpose, the well monitoring on the territory of the Petropavlovsk-Kamchatsky test site, Kamchatka Peninsula, was updated using Keller equipment, Switzerland (sensors of PAA36 XiW CTD Si, PAA36 XiW modifications, data logger GSM-2), Campbell Scientific Inc, USA (CR6 and CR1000 data loggers) and a budgetary hydrogeodynamic data recorder (HDDR) based on the STK-1 minicomputers, created at the Kamchatka Branch of the GS RAS. A description has been provided concerning the sets of digital equipment installed in four wells for precise recording of groundwater pressure variations with a frequency of 20.00–0.08 Hz. Consideration is being given to the characteristics of the equipment installed in individual wells and to the problems solved in the process of updating the well observation system in order to study vibration effects and hydrogeodynamic precursors of earthquakes. The paper presents the newly obtained results of recording the high-frequency variations in groundwater pressure in wells during the 2020–2021 local and remote earthquakes. A discussion is provided of new possibilities for studying vibration effects on changes in ground water pressure with a frequency comparable to the frequency of recording seismic events by seismometric equipment. Using a new equipment for recording water pressure in the unique well E-1 made it possible to record, a hydrogeodynamic precursor in real time before the March 16, 2021, Mw=6.6 earthquake which occurred at the epicentral distance of 350 km from the well

    Spectral and electroluminescent properties of coordination compounds of terbium (III) with ibuprofen (in solid form, chloroform solutions, and polyvinylcarbazole films)

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    Spectral properties of terbium (III) complexes with composition of TbL3DL, where L is an anion of d,l-2-(4-isobutylphenyl)propanoic acid (ibuprofen) and DL is 2,2β€²-dipyridyl (Dipy), 1,10-phenanthroline (Phen), or triphenylphosphine oxide (TPPO), have been studied in a solid form, chloroform solutions, and polyvinylcarbazole (PVC) films. It has been demonstrated that, in PVC films, occupation of the emitting level of terbium (III) involves the participation of polymer. The emission decay lifetimes of terbium in the chloroform solutions and PVC films have been measured. The possibility of the appearance of electroluminescence of complexes in PVC films has been studied
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