On the possibility of refining by means of optical location some astronomical parameters of the system - Earth-Moon

Optical location of moon in Earth-Moon system using artificial light reflector, on lunar surfac

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

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

Neutrino spin rotation in dense matter and electromagnetic field

Exact solutions of the Dirac--Pauli equation for massive neutrino with anomalous magnetic moment interacting with dense matter and strong electromagnetic field are found. The complete system of neutrino wavefunctions, which show spin rotation properties are obtained and their possible applications are discussed.Comment: 11 pages, latex, misprints are correcte

Test of an LED Monitoring System for the PHOS Spectrometer

Preprint submitted to Elsevier Print on 26th January 2000A prototype monitoring system for the Photon Spectrometer (PHOS) of the ALICE experiment at LHC is described in detail. The prototype consists of Control and Master modules. The first one is 8x8 matrix of Light Emitting Diodes coupled with stable generators of current pulses. The system provides an individual control for each of the 64 channels of PHOS prototype based on lead-tungstate crystals. A long term stability of order of 10-3 has been achieved in integral beam tests of the monitoring system and PHOS prototypes

A super massive black hole binary in 3C66B: future observational perspectives

Supermassive black hole binaries (SMBHBs) may exist in the centers of galaxies and active galactic nuclei (AGN) and are expected to be fairly common in the Universe as a consequence of merging processes between galaxies. The existence of SMBHBs can be probed by looking for double nuclei in galaxy centers or, more easily, detecting periodic behavior in the observed radio light curves. In a recent paper, Sudou et al. \cite{sudou2003} announced the first direct observation of an SMBHB. Using VLBI observations they found that the unresolved radio core of the radio galaxy 3C66B shows a well defined elliptical motion with a period of $1.05\pm 0.03$ yrs, implying the presence of a couple of massive black holes in the center of the galaxy. In the present paper we study the astrophysical implications of the existence of such an SMBHB in 3C66B. In particular we focus on the information that can be obtained from detecting a signal periodicity either in the $X$-ray and/or $\gamma$-ray light curves as a consequence of the motion of the black holes. These observations could be used to extract further information on the physical parameters of the SMBHB and partially solve the system parameter degeneracy. The detection of the gravitational wave spectrum emitted by such system may be used to completely determine the physical parameters of the binary system.Comment: 8 pages, 8 figures, in Press on Astronomy & Astrophysic

Эксплуатационные свойства газобетона с модифицированной поверхностью

Дослідження спрямоване на розроблення просочувальних композицій на основі кремнійорганічних речовин, модифікованих термопластичними полімерами, для просочення газобетону. Обробка отриманими композиціями дає можливість підвищити експлуатаційні властивості газобетонних виробів. Вирішення поставленого завдання досягалось через дослідження впливу модифікування поверхні газобетонних виробів просочувальними композиціями різних складу та концентрації. Двокомпонентні системи, що містили поліметилфенілсилоксанові смоли, модифікувалися поліметилметакрилатом у розчині толуолу. Отриманими розчинами просочувалися зразки газобетону, та після закінчення процесу модифікації визначалися основні фізико-механічні властивості виробів. За отриманими результатами встановлено, що найбільше підвищення експлуатаційних властивостей газобетону відбувається при просоченні композиціями з оптимальними співвідношенням та концентрацією компонентів у розчині.The purpose of work consists in development of impregnating with compositions on the basis of siliconorganic matters of modified by thermoplastic polymers for the impregnation of cellular concrete. Treatment the prepared compositions allow to promote operating properties of cellular concrete wares. The decision of this task was arrived by research of influence of surface retrofitting of cellular concrete wares by impregnating with compositions of different composition and concentration. Twocomponent systems which contained polymethylphenylsiloxane varnishes modified by polymethylenoxide in solution of toluene. The cellular concrete was leaked by prepared solutions and upon termination of modification process the basic physic-mechanical properties of wares was determined. It is set after they got results, that the most increase of operating properties of cellular concrete takes place at saturating with compositions with optimum correlation and concentration of components in solution.Исследование направлено на разработку пропитывающих композиций на основе кремнийорганических веществ, модифицированных термопластичными полимерами, для пропитки газобетона. Обработка полученными композициями позволяет повысить эксплуатационные свойства газобетонных изделий. Решение поставленного задания достигалось путем исследования влияния модифицирования поверхности газобетонных изделий пропитывающими композициями разных состава и концентрации. Двухкомпонентные системы, которые содержали полиметилфенилсилоксановые смолы, модифицировались полиметилметакрилатом в растворе толуола. Полученными растворами пропитывались образцы газобетона, и по окончании процесса модификации определялись основные физико-механические свойства изделий. За полученными результатами установлено, что наибольшее повышение эксплуатационных свойств газобетона происходит при пропитке композициями с оптимальными соотношением и концентрацией компонентов в растворе

Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine Scale Structure

We have used VLBA fringe visibility data obtained at 15 GHz to examine the compact structure in 250 extragalactic radio sources. For 171 sources in our sample, more than half of the total flux density seen by the VLBA remains unresolved on the longest baselines. There are 163 sources in our list with a median correlated flux density at 15 GHz in excess of 0.5 Jy on the longest baselines. For about 60% of the sources, we have at least one observation in which the core component appears unresolved (generally smaller than 0.05 mas) in one direction, usually transverse to the direction into which the jet extends. BL Lacs are on average more compact than quasars, while active galaxies are on average less compact. Also, in an active galaxy the sub-milliarcsecond core component tends to be less dominant. IDV sources typically have a more compact, more core-dominated structure on sub-milliarcsecond scales than non-IDV sources, and sources with a greater amplitude of intra-day variations tend to have a greater unresolved VLBA flux density. The objects known to be GeV gamma-ray loud appear to have a more compact VLBA structure than the other sources in our sample. This suggests that the mechanisms for the production of gamma-ray emission and for the generation of compact radio synchrotron emitting features are related. The brightness temperature estimates and lower limits for the cores in our sample typically range between 10^11 and 10^13 K, but they extend up to 5x10^13 K, apparently in excess of the equipartition brightness temperature, or the inverse Compton limit for stationary synchrotron sources. The largest component speeds are observed in radio sources with high observed brightness temperatures, as would be expected from relativistic beaming (abridged).Comment: 31 pages, 13 figures, 4 tables, accepted for publication in the Astronomical Journal; minor changes to the text are mad