87 research outputs found
Creation of automated control system of environmental safety of an industrial complex
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
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
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
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
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
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
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
The D-dimensional cosmological model on the manifold describing the evolution of 2 Einsteinian factor spaces,
and , 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
and the 2-component perfect fluid source.Comment: LaTeX file, no figure
On Observational Predictions from Multidimensional Gravity
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 and , 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 and 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 . 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
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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