3,585 research outputs found

    Covariant Treatment of Neutrino Spin (Flavour) Conversion in Matter under the Influence of Electromagnetic Fields

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    Within the recently proposed Lorentz invariant formalism for description of neutrino spin evolution in presence of an arbitrary electromagnetic fields effects of matter motion and polarization are considered.Comment: Extended version of contribution to "Particle Physics on Boundary of Millenniums" (Proceedings of the 9th Lomonosov Conference on Elementary Particle Physics, World Scientific, Singapure

    MODELING OF ADS-B MESSAGES TRANSMISSION VIA IRIDIUM SATELLITES COMMUNICATION CHANNEL

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    In this article the idea of ADS-B message transmission via communication channel by means of Iridium satellites was considered. The transmission model based on real parameters was created and investigated

    Multi-frequency investigation of the parsec- and kilo-parsec-scale radio structures in high-redshift quasar PKS 1402+044

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    We investigate the frequency-dependent radio properties of the jet of the luminous high-redshift (z = 3.2) radio quasar PKS 1402+044 (J1405+0415) by means of radio interferometric observations. The observational data were obtained with the VLBI Space Observatory Programme (VSOP) at 1.6 and 5 GHz, supplemented by other multi-frequency observations with the Very Long Baseline Array (VLBA; 2.3, 8.4, and 15 GHz) and the Very Large Array (VLA; 1.4, 5, 15, and 43 GHz). The observations span a period of 7 years. We find that the luminous high-redshift quasar PKS 1402+044 has a pronounced "core-jet" morphology from the parsec to the kilo-parsec scales. The jet shows a steeper spectral index and lower brightness temperature with increasing distance from the jet core. The variation of brightness temperature agrees well with the shock-in-jet model. Assuming that the jet is collimated by the ambient magnetic field, we estimate the mass of the central object as ~10^9 M_sun. The upper limit of the jet proper motion of PKS 1402+044 is 0.03 mas/yr (~3c) in the east-west direction.Comment: 9 pages, 6 figures

    Extragalactic Relativistic Jets and Nuclear Regions in Galaxies

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    Past years have brought an increasingly wider recognition of the ubiquity of relativistic outflows (jets) in galactic nuclei, which has turned jets into an effective tool for investigating the physics of nuclear regions in galaxies. A brief summary is given here of recent results from studies of jets and nuclear regions in several active galaxies with prominent outflows.Comment: 5 pages; contribution to ESO Astrophysical Symposia, "Relativistic Astrophysics and Cosmology", eds. B. Aschenbach, V. Burwitz, G. Hasinger, B. Leibundgut (Springer: Heidelberg 2006

    Statistical evaluation of the effect of hygrothermal aging on the interlaminar shear of GFRP

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    Π˜Π·ΡƒΡ‡Π΅Π½ΠΈΠ΅ закономСрностСй измСнСния свойств, накоплСния ΠΏΠΎΠ²Ρ€Π΅ΠΆΠ΄Π΅Π½ΠΈΠΉ ΠΈ Ρ€Π°Π·Ρ€ΡƒΡˆΠ΅Π½ΠΈΡ конструкционных ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ΠΎΠ² послС гигротСрмичСского старСния прСдставляСт собой Π°ΠΊΡ‚ΡƒΠ°Π»ΡŒΠ½ΠΎΠ΅ ΠΈ Π²Π°ΠΆΠ½ΠΎΠ΅ Π½Π°ΠΏΡ€Π°Π²Π»Π΅Π½ΠΈΠ΅. Π’ Ρ€Π°Π±ΠΎΡ‚Π΅ прСдставлСны Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ мСханичСских испытаний Π½Π° мСТслойный сдвиг ΠΎΠ±Ρ€Π°Π·Ρ†ΠΎΠ² элСктротСхничСского конструкционного стСклопластика ΠΈ эпоксидного ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π° Π΄ΠΎ ΠΈ послС ΠΏΡ€Π΅Π΄Π²Π°Ρ€ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠ³ΠΎ гигротСрмичСского старСния Π² Ρ€Π°Π±ΠΎΡ‡ΠΈΡ… срСдах (тСхничСская Π²ΠΎΠ΄Π°, морская Π²ΠΎΠ΄Π°, машинноС масло) Ρ€Π°Π·Π»ΠΈΡ‡Π½ΠΎΠΉ ΠΏΡ€ΠΎΠ΄ΠΎΠ»ΠΆΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ (15, 30 ΠΈ 45 суток. ) ΠΈ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€ (22, 60 ΠΈ 90ΒΊΠ‘). Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ испытаний Π±Ρ‹Π»ΠΈ ΠΈΡΠΏΠΎΠ»ΡŒΠ·ΠΎΠ²Π°Π½Ρ‹ для статистичСской ΠΎΡ†Π΅Π½ΠΊΠΈ значимости Π½Π΅ΠΌΠΎΠ½ΠΎΡ‚ΠΎΠ½Π½Ρ‹Ρ… ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ прочности Π² случаС мСТслойного сдвига послС ΠΏΡ€Π΅Π΄Π²Π°Ρ€ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠ³ΠΎ гигротСрмичСского старСния ΠΎΡ‚Π½ΠΎΡΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎ номинального ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»Π° с использованиСм ANCOVA ΠΈ рСгрСссионного Π°Π½Π°Π»ΠΈΠ·Π°. Π’Π°ΠΊΠΈΠ΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, Ρ‡Ρ‚ΠΎ морскиС ΠΈ тСхнологичСскиС Π²ΠΎΠ΄Π½Ρ‹Π΅ растворы ΠΎΡ‚Ρ€ΠΈΡ†Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎ Π²Π»ΠΈΡΡŽΡ‚ Π½Π° ΠΏΡ€ΠΎΡ‡Π½ΠΎΡΡ‚ΡŒ Π½Π° мСТслойный сдвиг, Π½ΠΎ ΠΈΡ… влияниС Π±Ρ‹Π»ΠΎ Π½Π΅ΠΌΠ½ΠΎΠ³ΠΎ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹ΠΌ ΠΈ сильно зависСло ΠΎΡ‚ эффСкта взаимодСйствия ΠΌΠ΅ΠΆΠ΄Ρƒ Π²Ρ€Π΅ΠΌΠ΅Π½Π΅ΠΌ воздСйствия ΠΈ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€ΠΎΠΉ раствора. Π’Π°ΠΊΠΈΠΌ ΠΎΠ±Ρ€Π°Π·ΠΎΠΌ, максимальная Ρ€Π°Π·Π½ΠΈΡ†Π° составляСт ΠΎΠΊΠΎΠ»ΠΎ 15% ΠΈ 12% послС 45 Π΄Π½Π΅ΠΉ Π²Π½ΡƒΡ‚Ρ€ΠΈ тСхнологичСской ΠΈ морской Π²ΠΎΠ΄Ρ‹ ΠΏΡ€ΠΈ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π΅ 90 ΒΊC соотвСтствСнно. Напротив, воздСйствиС машинного масла ΠΏΡ€ΠΈΠ²Π΅Π»ΠΎ ΠΊ ΡƒΠ²Π΅Π»ΠΈΡ‡Π΅Π½ΠΈΡŽ прочности, Π½ΠΎ эффСкт Π±ΠΎΠ»Π΅Π΅ слабый ΠΏΠΎ ΡΡ€Π°Π²Π½Π΅Π½ΠΈΡŽ с Π²ΠΎΠ΄Π½Ρ‹ΠΌΠΈ растворами (ΠΎΠΊΠΎΠ»ΠΎ 6%)

    Practical analytical solutions for benchmarking of 2-D and 3-D geodynamic Stokes problems with variable viscosity

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    Geodynamic modeling is often related with challenging computations involving solution of the Stokes and continuity equations under the condition of highly variable viscosity. Based on a new analytical approach we have developed particular analytical solutions for 2-D and 3-D incompressible Stokes flows with both linearly and exponentially variable viscosity. We demonstrate how these particular solutions can be converted into 2-D and 3-D test problems suitable for benchmarking numerical codes aimed at modeling various mantle convection and lithospheric dynamics problems. The Main advantage of this new generalized approach is that a large variety of benchmark solutions can be generated, including relatively complex cases with open model boundaries, non-vertical gravity and variable gradients of the viscosity and density fields, which are not parallel to the Cartesian axes. Examples of respective 2-D and 3-D MatLab codes are provided with this paper

    VSOP observation of the quasar PKS 2215+020: a new laboratory for core-jet physics at z=3.572

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    We report results of a VSOP (VLBI Space Observatory Programme) observation of a high redshift quasar PKS 2215+020 (z=3.572). The ~1 milliarcsecond resolution image of the quasar reveals a prominent `core-jet' structure on linear scales from 5/h to 300/h pc ($H_0=100*h km/(s*Mpc). The brightness temperatures and sizes of bright features identified in the jet are consistent with emission from relativistic shocks dominated by adiabatic energy losses. The jet is powered by the central black hole with estimated mass of ~4*10^9 solar masses. Comparisons with VLA and ROSAT observations indicate a possible presence of an extended radio/X-ray halo surrounding 2215+020.Comment: 15 pages, 6 figures, aastex macros; accepted for publication in The Astrophysical Journal, V.546, N.2 *(January 10 2001

    Mechanochemical conversion of acetylene in quartz – ultrafine metal powder system

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    We have studied the effect of nano-sized metal powders (Zn, Ni), obtained by electric explosion of wires, on mechanochemical conversions of acetylene in the presence of quartz. In the process of acetylene mechanical treatment (MT) in the presence of quartz, benzene is formed. During the mechanical grinding of quartz in planetary-centrifugal mills, active radical sites are formed on quartz surface. It is possible to suppose that due to the influence of mechanical energy acetylene triple bond breaks to form ethyl radicals, which are subjected to chemosorption on active quartz sites with subsequent formation of benzene. The addition of ultrafine Zn powder decreased, while Ni powder considerably increased benzene yield. In the process of MT, particles of ultrafine Zn powder are agglomerated which results in the decrease of its catalytic activity. The increase in benzene yield at the use of ultrafine Ni powder as the additives is associated with catalytic conversion of acetylene into benzene on the newly formed nickel surface. The injection of ultrafine Zn and Ni powders in quartz-acetylene system caused no changes in quantitative composition of acetylene conversion products but affected the amounts of one or other component formation
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