87 research outputs found

    Creation of automated control system of environmental safety of an industrial complex

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    This article presents the methodological approaches to the creation of modern automated control systems of environmental safety of an industrial complex, endowed with the property of rapid response in real time on the dynamics of the current environmental situatio

    Composite fluxbranes with general intersections

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    Generalized composite fluxbrane solutions for a wide class of intersection rules are obtained. The solutions are defined on a manifold which contains a product of n Ricci-flat spaces M_1 x ... x M_n with 1-dimensional M_1. They are defined up to a set of functions H_s obeying non-linear differential equations equivalent to Toda-type equations with certain boundary conditions imposed. A conjecture on polynomial structure of governing functions H_s for intersections related to semisimple Lie algebras is suggested. This conjecture is valid for Lie algebras: A_m, C_{m+1}, m > 0. For simple Lie algebras the powers of polynomials coincide with the components of the dual Weyl vector in the basis of simple roots. Explicit formulas for A_1 + ... + A_1 (orthogonal), "block-ortogonal" and A_2 solutions are obtained. Certain examples of solutions in D = 11 and D =10 (II A) supergravities (e.g. with A_2 intersection rules) and Kaluza-Klein dyonic A_2 flux tube, are considered.Comment: 19 pages, Latex, 1 reference (on a pioneering paper of Gibbons and Wiltshire) and two missing relations are added Published: Class. Quantum Grav. 19 (2002) 3033-304

    Models of G time variations in diverse dimensions

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    A review of different cosmological models in diverse dimensions leading to a relatively small time variation of the effective gravitational constant G is presented. Among them: 4-dimensional general scalar-tensor model, multidimensional vacuum model with two curved Einstein spaces, multidimensional model with multicomponent anisotropic "perfect fluid", S-brane model with scalar fields and two form field etc. It is shown that there exist different possible ways of explanation of relatively small time variation of the effective gravitational constant G compatible with present cosmological data (e.g. acceleration): 4-dimensional scalar-tensor theories or multidimensional cosmological models with different matter sources. The experimental bounds on G-dot may be satisfied ether in some restricted interval or for all allowed values of the synchronous time variable.Comment: 27 pages, Late

    Predicting the operational efficiency of high-pressure roller crushers

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    Models based on regression analysis for predicting the operational efficiency of high-pressure roller crushers are considered. A systematized and structured production database is created and statistically analyzed. The consistency of the data is verified. The parameters with the greatest influence on the productivity are identified. The basic structure of the mathematical models is determined, and the limits on their applicability are assessed. Predictive mathematical models are developed. Their adequacy is verified, and their precision is established in assessing the productivity of mills at an enrichment plant where the mineral composition of the incoming ore varie

    Possibility of using dielectric channels as deflecting systems for controlling accelerated electron beams

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    The results of an investigation of the passage of 10-keV electron beam through dielectric channels fabricated from ceramic (zirconium dioxide) and pyroelectric crystals (lithium niobate) are presented. The angle of deflection of the electron beam by the channels was measured as a function of the angle of interaction of the beam with the internal walls of the channels. The obtained results indicate the possible prospects of using dielectric surfaces as effective deflectors of accelerated charged particl

    Piezoelectric accelerator

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    Here we propose the conception of small-size piezoelectric accelerator of charged particles that operates due to the piezoelectric effect at varying mechanical force applied to piezoelectrics in vacuum. The accelerating voltage and the energy of accelerated particles are estimated. In the proof-of-principle experiment we demonstrate the effect of the emission of X-ray radiation at the mechanical compression of piezoelectric ceramics in vacuu

    Optimal speed of temperature change of a crystal in a pyroelectric X-ray radiation source

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    In this work we present the results of the experimental studies of the dependence of the X-ray radiation on the temperature change speed of the lithium tantalate monocrystal in the pyroelectric source of the X-ray radiation. We have found an optimized linear temperature speed change pattern for the pyroelectric crystal designed for generation of the X-ray radiation with enhanced capabilitie

    Integration of D-dimensional 2-factor spaces cosmological models by reducing to the generalized Emden-Fowler equation

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    The D-dimensional cosmological model on the manifold M=R×M1×M2M = R \times M_{1} \times M_{2} describing the evolution of 2 Einsteinian factor spaces, M1M_1 and M2M_2, in the presence of multicomponent perfect fluid source is considered. The barotropic equation of state for mass-energy densities and the pressures of the components is assumed in each space. When the number of the non Ricci-flat factor spaces and the number of the perfect fluid components are both equal to 2, the Einstein equations for the model are reduced to the generalized Emden-Fowler (second-order ordinary differential) equation, which has been recently investigated by Zaitsev and Polyanin within discrete-group analysis. Using the integrable classes of this equation one generates the integrable cosmological models. The corresponding metrics are presented. The method is demonstrated for the special model with Ricci-flat spaces M1,M2M_1,M_2 and the 2-component perfect fluid source.Comment: LaTeX file, no figure

    On Observational Predictions from Multidimensional Gravity

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    We discuss possible observational manifestations of static, spherically symmetric solutions of a class of multidimensional theories of gravity, which includes the low energy limits of supergravities and superstring theories as special cases. We discuss the choice of a physical conformal frame to be used for the description of observations. General expressions are given for (i) the Eddington parameters β\beta and γ\gamma, characterizing the post-Newtonian gravitational field of a central body, (ii) p-brane black hole temperatures in different conformal frames and (iii) the Coulomb law modified by extra dimensions. It is concluded, in particular, that β\beta and γ\gamma depend on the integration constants and can be therefore different for different central bodies. If, however, the Einstein frame is adopted for describing observations, we always obtain γ=1\gamma=1. The modified Coulomb law is shown to be independent of the choice of a 4-dimensional conformal frame. We also argue the possible existence of specific multidimensional objects, T-holes, potentially observable as bodies with mirror surfaces.Comment: 16 pages, Latex2

    Semiconductor driver of pyroelectric accelerator of charged particles

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    The possibility for application of semiconductor element for heating of pyroelectric crystalin a pyroelectric accelerator of charged particles or pyroelectric X-ray generator is at first proposed and demonstrated experimentally. Spectra of X-ray radiation measured at the heating of the pyroelectric crystal LiNbO3 by silicon diode at different pressures of residual gas are presente
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