A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars

In an earlier paper, we introduced a model for pulsars in which non-radial oscillations of high spherical degree (\el) aligned to the magnetic axis of a spinning neutron star were able to reproduce subpulses like those observed in single-pulse measurements of pulsar intensity. The model did not address polarization, which is an integral part of pulsar emission. Observations show that many pulsars emit radio waves that appear to be the superposition of two linearly polarized emission modes with orthogonal polarization angles. In this paper, we extend our model to incorporate linear polarization. As before, we propose that pulsational displacements of stellar material modulate the pulsar emission, but now we apply this modulation to a linearly-polarized mode of emission, as might be produced by curvature radiation. We further introduce a second polarization mode, orthogonal to the first, that is modulated by pulsational velocities. We combine these modes in superposition to model the observed Stokes parameters in radio pulsars.Comment: 19 pages, 4 figures accepted Ap

210th anniversary of the Geology Museum of the Kazan University

The Geology Museum was founded in November 1805 though some collections date back to the 18th century. At first the Chamber for Natural History was initiated by the Kazan University, where a collection of specimens, either received from givers or bought from private individuals, and the Great Northern Expedition materials were exhibited. The curator of the Chamber became K. F. Fuks who participated in the Ural expedition. His contribution replenished the collection with valuable minerals (gold, silver, copper). From different corners of Russia, the University was given with specimens of rocks, minerals and petrifactions. Furthermore, the University bought equipment and exhibits required for natural history course training. By 1840 the Chamber held more than 19 thousand exhibition samples of minerals, ores and rocks. As it stood, the Chamber lived until 1865 as an auxiliary educational establishment for geology

Shock-Wave Experiment with the Chelyabinsk LL5 Meteorite : Experimental Parameters and the Texture of the Shock-Affected Material

A spherical geometry shock experiment with the light-colored lithology material of the Chelyabinsk LL5 ordinary chondrite was carried out. The material was affected by shock and thermal metamorphism whose grade ranged from initial stage S3-4 to complete melting. The temperature and pressure were estimated at >2000 degrees C and >90 GPa. The textural shock effects were studied by optical and electron microscopy. A single experimental impact has produced the whole the range of shock pressures and temperatures and, correspondingly, four zones identified by petrographic analysis: (1) a melt zone, (2) a zone of melting silicates, (3) a black ring zone, and (4) a zone of weakly shocked initial material. The following textural features of the material were identified: displacement of the metal and troilite phases from the central melt zone; the development of a zone of mixed lithology (light-colored fragments in silicate melt); the origin of a dark-colored lithology ring; and the generation of radiating shock veinlets. The experimental sample shows four textural zones that correspond to the different lithology types of the Chelyabinsk LL5 meteorite found in fragments of the meteoritic shower in the collection at the Ural Federal University. Our results prove that shock wave loading experiment can be successfully applied in modeling of space shocks and can be used to experimentally model processes at the small bodies of the solar system.Peer reviewe

Structure and electrical conductivity of cobalt-doped Bi 26Mo10O69

The existence boundaries, structures, and transport parameters of Bi 1 - x Co x [Bi12O14]Mo 5O20 ± δ and Bi[Bi12O 14]Mo5 - y Co y O20 ± δ solid solutions, which have a unique columnar structure, were studied. Electrical conductivity in these solid solutions was studied by impedance spectroscopy. © 2013 Pleiades Publishing, Ltd