Sterlitamak State Pedagogical Academy

Sterlitamak, Russia

Sterlitamak State Pedagogical Academy

Sterlitamak, Russia
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Bhattacharya A.,North Bengal University | Potapov A.A.,Sterlitamak State Pedagogical Academy
Modern Physics Letters A | Year: 2010

A recent work by Dey and Sen derived the approximate light deflection angle α by an Ellis wormhole in terms of proper radial distance ℓ that covers the entire spacetime. On the other hand, Bodenner and Will calculated the expressions for light bending in Schwarzschild geometry using various coordinates and showed that they all reduce to a single formula when re-expressed in the coordinate independent language of "circumferential radius" rC identified with the standard radial coordinate r S. We shall argue that the coordinate invariant language for two-way wormholes should be ℓ rather than rS. Hence here we find the exact deflection α in Ellis wormhole geometry first in terms of ℓ and then in terms of rS. We confirm the latter expression using three different methods. We argue that the practical measurement scheme does not necessarily single out either ℓ or rS. Some errors in the literature are corrected. © 2010 World Scientific Publishing Company.

Filippov A.I.,Sterlitamak State Pedagogical Academy | Nandi K.K.,North Bengal University | Fattakhov R.G.,Sterlitamak State Pedagogical Academy | Ishmuratov T.A.,Sterlitamak State Pedagogical Academy
High Temperature | Year: 2012

The dependence of thermal fields on the parameters of petroleum bitumens and oil skimmer were analyzed on the basis of the modified Stefan problem solution as a kinematic wave, taking into account the melting zone is formed in a limited range of temperatures. © 2012 Pleiades Publishing, Ltd.

Kyzyrgulov I.R.,Sterlitamak State Pedagogical Academy | Khusainov A.T.,Bashkir State University | Kharrasov M.K.,Bashkir State University
Russian Physics Journal | Year: 2010

The gauge theory of dislocations and disclinations in crystals with polyatomic lattice is generalized to ferroelastic interactions. In this work, based on the SO(3N)λT(3N) gauge group, an unbouned isotropic continuous medium comprising dislocations and disclinations is used to model an actual crystal, where N is the number of atoms per unit cell and λ is the sign of a semidirect product. © 2010 Springer Science+Business Media, Inc.

Lepikhin S.A.,Birsk State Social and Pedagogical Academy | Galimzyanov M.N.,Russian Academy of Sciences | Gimaltdinov I.K.,Sterlitamak State Pedagogical Academy
High Temperature | Year: 2010

Special features are investigated of the initiation of detonation waves in chemically active bubble media located in channels of variable cross section. It is found that, depending on the initial volume content of combustible mixture, the detonation in convergent channels may proceed with the emergence of one or two detonation solitons. The possibility of the emergence of a stable detonation wave upon reflection from the channel bottom is demonstrated in channels with closed bottom. Also demonstrated is the possibility of initiation of detonation upon reflection of the wave from the region of "pure" liquid. Depending on the amplitude of initiating wave and of the initial volume content of bubbles, a map of solutions is constructed which illustrates the modes of the process of detonation in the considered channels. © 2010 Pleiades Publishing, Ltd.

Kaliev I.A.,Sterlitamak State Pedagogical Academy | Sabitova M.M.,Sterlitamak State Pedagogical Academy
Journal of Applied and Industrial Mathematics | Year: 2010

Under consideration are the three problems that simulate the process of determining the temperature and density of heat sources from some given initial and final temperatures. In the course of their mathematical formulation, some inverse problems arise for the heat transfer equation in which, together with the solution of the equation, one needs also to find the unknown right-hand side that depends only on the spatial variable. The existence and uniqueness theorems are proved for the solution. © 2010 Pleiades Publishing, Ltd.

Khasanov M.K.,Sterlitamak State Pedagogical Academy | Gimaltdinov I.K.,Sterlitamak State Pedagogical Academy | Stolpovsky M.V.,Sterlitamak State Pedagogical Academy
Theoretical Foundations of Chemical Engineering | Year: 2010

A mathematical model of the process of the formation of gas hydrates in a porous medium during the injection of a cold gas is presented. The cases where hydrate formation is limited by the kinetics of the process and heat and mass transfer in a porous medium are considered. The influence of the initial parameters of the porous medium and the intensity of the gas injection on the dynamics of the processes of hydrate formation is studied. The critical conditions that separate the different modes of hydrate formation are found. © 2010 Pleiades Publishing, Ltd.

Rakhmatullin R.R.,Sterlitamak State Pedagogical Academy | Levashova V.I.,Sterlitamak State Pedagogical Academy | Dekhtyar' T.F.,Sterlitamak State Pedagogical Academy
Petroleum Chemistry | Year: 2013

Quaternary ammonium salts have been synthesized from piperidine and alkenyl halides (4-chloropent-2-ene, 2-methyl-3-chlorobut-1-ene, 3-methyl-3-chlorobut- 1-ene), and their structure has been confirmed. The optimal synthesis conditions have determined, and the product compounds have been to serve as efficient bactericides against sulfate-reducing bacteria. © 2013 Pleiades Publishing, Ltd.

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