231 research outputs found

    Magnesium-Containing Slurry as Technogenic Alternative Raw Material for Magnesium Oxychloride Cement

    Get PDF
    It has been shown experimentally that a waste of magnesium metal production is a realistic alternative to naturally occurring cement raw materials. The waste is the carnallite slurry forming during the chlorination stage. The slurry contains magnesium oxide (MgO) and magnesium chloride (MgCl2) in a mass ratio close to their optimal ratio when preparing Sorel cement. It is found that the magnesium oxide in the slurry is highly reactive. MgO extracted from the slurry and MgCl2 solution are mixed forming homogeneous magnesium oxychloride cement (MOC) paste in which bonding crystalline structures typical for Sorel cement are formed during hardening. © 2019 Published under licence by IOP Publishing Ltd

    Synthesis and sorption properties of filled fibrous sorbents with immobilized hetarylformazan groups

    Get PDF
    New sorbents were prepared by immobilization of structurally different sulfur-containing hetaryl-formazans on nonwoven polyacrylonitrile fiber tilled with AV-17 anion exchanger. Sorption of some heavy metals on these materials was studied as influenced by various factors. Sorbents for selective recovery of copper(II) in the presence of nickel(II), zinc(II), and cadmium(II) cations were found

    Synthesis and catalytic properties of copper(II) 1-aryl-5-benzothiazolylformazanates

    Get PDF
    New copper(II) benzothiazolylformazane complexes were synthesized and immobilized on AN-18 anion exchanger. The influence of the composition of the coordination core of copper(II) benzthiazolylformazanates and temperature on their catalytic properties in decomposition of H2O2 and oxidation of Na2S in aqueous solution was studied

    Galactic Binary Gravitational Wave Noise within LISA Frequency Band

    Get PDF
    Gravitational wave noise associated with unresolved binary stars in the Galaxy is studied with the special aim of determining the upper frequency at which it stops to contribute at the rms noise level of the proposed space-born interferometer (LISA). The upper limit to this background is derived from the statistics of SN Ia explosions, part of which can be triggered by binary white dwarf coalescences. The upper limiting frequency at which binary stochastic noise crosses LISA rms sensitivity is found to lie within the range 0.03-0.07 Hz, depending on the galactic binary white dwarf coalescence rate. To be reliably detectable by LISA, the energy density of relic cosmological background per logarithmic frequency interval should be Omega_{GW}h_{100}^2>10^{-8} at f>0.03 Hz.Comment: 16 pages with 1 eps figure, aasms4.sty, to appear in the ApJ vol. 494 February 20, 1998 issu

    Trans-sonic propeller stage

    Full text link
    We follow the approach used by Davies and Pringle (1981) and discuss the trans-sonic substage of the propeller regime. This substage is intermediate between the supersonic and subsonic propeller substages. In the trans-sonic regime an envelope around a magnetosphere of a neutron star passes through a kind of a reorganization process. The envelope in this regime consists of two parts. In the bottom one turbulent motions are subsonic. Then at some distance rsr_\mathrm{s} the turbulent velocity becomes equal to the sound velocity. During this substage the boundary rsr_\mathrm{s} propagates outwards till it reaches the outer boundary, and so the subsonic regime starts. We found that the trans-sonic substage is unstable, so the transition between supersonic and subsonic substages proceeds on the dynamical time scale. For realistic parameters this time is in the range from weeks to years.Comment: 8 pages with figures, submitted to Astron. Astroph. Transaction

    Synthesis and spectroscopic features of iron(II) 1-aryl-5-benzothiazol-2- ylformazanates

    Get PDF
    New iron(II) coordination compounds with 1-aryl-5-(benzothiazol-2-yl) formazans were prepared. Their compositions and structures were determined by electronic spectroscopy, mass spectrometry, single crystal X-ray diffraction analysis, and magnetochemical measurements. © 2008 Pleiades Publishing, Ltd.Russian Foundation for Basic Researc

    Luminosity function of binary X-ray sources calculated using the Scenario Machine

    Full text link
    Using the ``Scenario Machine'' we have carried out a population synthesis of X-ray binaries for the purpose of modelling of X-ray luminosity functions (XLFs) in different types of galaxies: star burst, spiral, and elliptical. This computer code allows to calculate, by using Monte Carlo simulations, the evolution of a large ensemble of binary systems, with proper accounting for the spin evolution of magnetized neutron stars. We show that the XLF has no universal type. It depends on the star formation rate in the galaxy. Also it is of importance to take into account the evolution of binary systems and life times of X-ray stages in theoretical models of such functions. We have calculated cumulative and differential XLFs for the galaxy with the constant star formation rate. Also we have calculated cumulative luminosity functions for different intervals of time after the star formation burst in the galaxy and curves depicting the evolution of the X-ray luminosity after the star formation burst in the galaxy.Comment: 22 pages, 13 figure

    The Economic Foundations of the Rule of Law in the Russian Federation

    Get PDF
    This study, based on the economic and legal metrics of the Russian Federation, considers the possibility of implementing the concept of the rule of law in the modern world. The study emphasises the issue of the rule of law in any country being directly related to the problem of redistribution of public goods. In many ways, this can be considered an example of how economic stability ensures legal stability. The research methodology includes a dialectical method, which allowed to ensure compliance with the principles of scientific knowledge. The study shows the dynamics of ensuring human rights, the distribution of income and expenses in society over different periods in the history of the Russian Federation. In this regard, the authors come to the conclusion that the perception and functions of the concept of the rule of law will soon deviate from classical liberal values towards the basic ideas of social equality and justice

    Population synthesis of old neutron stars in the Galaxy

    Get PDF
    The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a statistical sample of stars for different values of the initial kick velocity, drawn from an isotropic Gaussian distribution with mean velocity 0<V>5500\leq < V>\leq 550 kms1{\rm km s^{-1}}. The spin-down, induced by dipole losses and the interaction with the ambient medium, is tracked together with the dynamical evolution in the Galactic potential, allowing for the determination of the fraction of stars which are, at present, in each of the four possible stages: Ejector, Propeller, Accretor, and Georotator. Taking from the ROSAT All Sky Survey an upper limit of 10\sim 10 accreting neutron stars within 140\sim 140 pc from the Sun, we infer a lower bound for the mean kick velocity, \ga 200-300 kms1{\rm km s^{-1}}. The same conclusion is reached for both a constant (B1012B\sim 10^{12} G) and a magnetic field decaying exponentially with a timescale 109\sim 10^9 yr. Present results, moreover, constrain the fraction of low velocity stars, which could have escaped pulsar statistics, to \la 1%.Comment: 8 pages, 4 PostScript figures, to appear in the proceedings of IAU Symposium 19
    corecore