478 research outputs found
A note on the breathing mode of an elastic sphere in Newtonian and complex fluids
Experiments on the acoustic vibrations of elastic nanostructures in fluid
media have been used to study the mechanical properties of materials, as well
as for mechanical and biological sensing. The medium surrounding the
nanostructure is typically modeled as a Newtonian fluid. A recent experiment
however suggested that high-frequency longitudinal vibration of bipyramidal
nanoparticles could trigger a viscoelastic response in water-glycerol mixtures
[M. Pelton et al., "Viscoelastic flows in simple liquids generated by vibrating
nanostructures," Phys. Rev. Lett. 111, 244502 (2013)]. Motivated by these
experimental studies, we first revisit a classical continuum mechanics problem
of the purely radial vibration of an elastic sphere, also called the breathing
mode, in a compressible viscous fluid, and then extend our analysis to a
viscoelastic medium using the Maxwell fluid model. The effects of fluid
compressibility and viscoelasticity are discussed. Although in the case of
longitudinal vibration of bipyramidal nanoparticles, the effects of fluid
compressibility were shown to be negligible, we demonstrate that it plays a
significant role in the breathing mode of an elastic sphere. On the other hand,
despite the different vibration modes, the breathing mode of a sphere triggers
a viscoelastic response in water-glycerol mixtures similar to that triggered by
the longitudinal vibration of bipyramidal nanoparticles. We also comment on the
effect of fluid viscoelasticity on the idea of destroying virus particles by
acoustic resonance
Emission spectrum of a dipole in a semi-infinite periodic dielectric structure: effect of the boundary
Journal ArticleThe emission spectrum of a dipole embedded in a semi-infinite photonic crystal is calculated. For simplicity we study the case in which the dielectric function is sinusoidally modulated only along the direction perpendicular to the boundary surface plane. In addition to oscillations of the emission rate with the distance of the dipole from the interface, we also observed that the shape of the emission spectrum srongly depends on the initial phase of the dielectric modulation. When the direction of light propagation inside the periodic structure is not normal to the boundary surface plane, we observed aditional singularities in the emission spectrum, which arise due to different angle dependence of the Bragg stop band for TE and TM polarizations
About the continuity of one operation with convex compacts in finite-dimensional normed spaces
In this paper, we study the deformation of the intersection of one compact
set with a closed neighborhood of another compact set by changing the radius of
this neighborhood. It is shown that in finite-dimensional normed spaces, in the
case when both compact sets are non-empty convex subsets, such an operation is
continuous in the topology generated by the Hausdorff metric. The question of
the continuous dependence of the described intersection on the radius of the
neighborhood arose as a by-product of the development of the theory of extremal
networks. However, it turned out to be interesting in itself, suggesting
various generalizations. Therefore, it was decided to publish it separately.Comment: in Russian languag
ΠΡΠ΅Π½ΠΊΠ° Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π½Π°Π»ΠΎΠ³ΠΎΠ²ΠΎ-Π±ΡΠ΄ΠΆΠ΅ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ Π½Π° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡ Π² Π Π΅ΡΠΏΡΠ±Π»ΠΈΠΊΠ΅ ΠΡΠΌΠ΅Π½ΠΈΡ
Fiscal policy plays a crucial role in ensuring economic growth and development in the country and overcoming economic recessions. The subject of the research is the tax system in the Republic of Armenia. The study aims to identify and assess the impact of the fiscal policy on economic growth in the Republic of Armenia. Since the global financial crisis of 2008, the Armenian economy has been in stagnation, reaching pre-crisis GDP levels only in 2018. Both theory and practice point to the ambiguous nature of the impact of fiscal policy on economic growth. At the same time, the 2020 crisis caused by the pandemic exacerbated the situation by focusing the attention of economists on fiscal policy to stimulate the real sector of the economy, which justifies the relevance of the current study. The paperβs novelty lies in assessing the impact of certain types of taxes on the economic growth rates in Armenia. To achieve the goal of the study, the authors use such methods as a comparative analysis of foreign studies and systemic and statistical analysis. To econometrically assess the impact of taxes on economic growth in the country, a vector autoregression (VAR) model was applied. As a result of the study, the authors found that both tax regulation in general and the individual taxes are restrictive in nature and have a negative impact on economic growth in the country. The authors conclude that such a restrictive policy has led to a slowdown in economic growth in the Republic of Armenia over the past decadesΠ€ΠΈΡΠΊΠ°Π»ΡΠ½Π°Ρ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠ° ΠΈΠ³ΡΠ°Π΅Ρ ΠΊΠ»ΡΡΠ΅Π²ΡΡ ΡΠΎΠ»Ρ ΠΊΠ°ΠΊ Π² Β ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠ΅Π½ΠΈΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ° ΠΈ Β ΡΠ°Π·Π²ΠΈΡΠΈΡ Π² Β ΡΡΡΠ°Π½Π΅, ΡΠ°ΠΊ ΠΈ Β Π² Β ΠΏΡΠ΅ΠΎΠ΄ΠΎΠ»Π΅Π½ΠΈΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠΏΠ°Π΄ΠΎΠ². ΠΡΠ΅Π΄ΠΌΠ΅ΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ Π½Π°Π»ΠΎΠ³ΠΎΠ²ΠΎ-Π±ΡΠ΄ΠΆΠ΅ΡΠ½Π°Ρ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠ° Π Π΅ΡΠΏΡΠ±Π»ΠΈΠΊΠΈ ΠΡΠΌΠ΅Π½ΠΈΡ (Π Π). Π¦Π΅Π»Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ β Π²ΡΡΠ²Π»Π΅Π½ΠΈΠ΅ ΠΈ ΠΎΡΠ΅Π½ΠΊΠ° Π²Π»ΠΈΡΠ½ΠΈΡ Π½Π°Π»ΠΎΠ³ΠΎΠ²ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ Π½Π° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡ Π² Π Π. ΠΠΎΡΠ»Π΅ Π³Π»ΠΎΠ±Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΈΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΠΊΡΠΈΠ·ΠΈΡΠ° 2008 Π³. ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠ° ΠΡΠΌΠ΅Π½ΠΈΠΈ Π½Π°Ρ
ΠΎΠ΄ΠΈΡΡΡ Π² ΡΡΠ°Π³Π½Π°ΡΠΈΠΈ, Π΄ΠΎΡΡΠΈΠ³Π½ΡΠ² ΠΏΡΠ΅Π΄ΠΊΡΠΈΠ·ΠΈΡΠ½ΠΎΠ³ΠΎ ΡΡΠΎΠ²Π½Ρ ΠΠΠ ΡΠΎΠ»ΡΠΊΠΎ Π² 2018 Π³. ΠΠ°ΠΊ ΡΠ΅ΠΎΡΠΈΡ, ΡΠ°ΠΊ ΠΈ ΠΏΡΠ°ΠΊΡΠΈΠΊΠ° ΡΠΊΠ°Π·ΡΠ²Π°ΡΡ Π½Π° Π½Π΅ΠΎΠ΄Π½ΠΎΠ·Π½Π°ΡΠ½ΡΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΡΠΈΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ Π½Π° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡ Π² ΡΠΎ Π²ΡΠ΅ΠΌΡ, ΠΊΠ°ΠΊ ΠΊΡΠΈΠ·ΠΈΡ 2020 Π³., Π²ΡΠ·Π²Π°Π½Π½ΡΠΉ ΠΏΠ°Π½Π΄Π΅ΠΌΠΈΠ΅ΠΉ, ΠΎΠ±ΠΎΡΡΡΠΈΠ» ΡΠΈΡΡΠ°ΡΠΈΡ, ΡΡΠΎΠΊΡΡΠΈΡΠΎΠ²Π°Π² Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΡΠΎΠ² Π½Π° Π½Π°Π»ΠΎΠ³ΠΎΠ²ΠΎ-Π±ΡΠ΄ΠΆΠ΅ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠ΅ Π΄Π»Ρ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ΅Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠ΅ΠΊΡΠΎΡΠ° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ, ΡΡΠΎ ΠΈ ΠΎΠ±ΠΎΡΠ½ΠΎΠ²ΡΠ²Π°Π΅Ρ Π°ΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ Π½Π°ΡΡΠΎΡΡΠ΅Π³ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ. ΠΠΎΠ²ΠΈΠ·Π½Π° ΡΠ°Π±ΠΎΡΡ ΡΠΎΡΡΠΎΠΈΡ Π² ΠΎΡΠ΅Π½ΠΊΠ΅ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΎΡΠ΄Π΅Π»ΡΠ½ΡΡ
Π²ΠΈΠ΄ΠΎΠ² Π½Π°Π»ΠΎΠ³ΠΎΠ² Π½Π° ΡΠ΅ΠΌΠΏΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ° Π² ΠΡΠΌΠ΅Π½ΠΈΠΈ. ΠΠ»Ρ Π΄ΠΎΡΡΠΈΠΆΠ΅Π½ΠΈΡ ΠΏΠΎΡΡΠ°Π²Π»Π΅Π½Π½ΠΎΠΉ ΡΠ΅Π»ΠΈ Π°Π²ΡΠΎΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΡΡ ΡΠ°ΠΊΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄Ρ, ΠΊΠ°ΠΊ ΡΡΠ°Π²Π½ΠΈΡΠ΅Π»ΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· Π·Π°ΡΡΠ±Π΅ΠΆΠ½ΡΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ, ΡΠΈΡΡΠ΅ΠΌΠ½ΡΠΉ ΠΈ ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈΠΉ Π°Π½Π°Π»ΠΈΠ·. Π ΡΠ΅Π»ΡΡ
ΡΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΡΠ΅Π½ΠΊΠΈ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π½Π°Π»ΠΎΠ³ΠΎΠ² Π½Π° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡ Π² ΡΡΡΠ°Π½Π΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½Π° ΠΌΠΎΠ΄Π΅Π»Ρ Π²Π΅ΠΊΡΠΎΡΠ½ΠΎΠΉ Π°Π²ΡΠΎΡΠ΅Π³ΡΠ΅ΡΡΠΈΠΈ (VAR). Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π°Π²ΡΠΎΡΠ°ΠΌΠΈ Π±ΡΠ»ΠΎ Π²ΡΡΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΊΠ°ΠΊ Π½Π°Π»ΠΎΠ³ΠΎΠ²ΠΎΠ΅ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π² ΡΠ΅Π»ΠΎΠΌ, ΡΠ°ΠΊ ΠΈ ΠΏΠΎ ΠΎΡΠ΄Π΅Π»ΡΠ½ΡΠΌ Π½Π°Π»ΠΎΠ³Π°ΠΌ Π½ΠΎΡΠΈΡ ΡΠ΄Π΅ΡΠΆΠΈΠ²Π°ΡΡΠΈΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ ΠΈ ΠΈΠΌΠ΅Π΅Ρ Π½Π΅Π³Π°ΡΠΈΠ²Π½ΠΎΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΡΠ΅ΠΌΠΏΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ° Π² ΡΡΡΠ°Π½Π΅. Π‘Π΄Π΅Π»Π°Π½ Π²ΡΠ²ΠΎΠ΄, ΡΡΠΎ ΡΠ°ΠΊΠ°Ρ ΡΠ΄Π΅ΡΠΆΠΈΠ²Π°ΡΡΠ°Ρ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠ° Π½Π° ΠΏΡΠΎΡΡΠΆΠ΅Π½ΠΈΠΈ ΠΏΠΎΡΠ»Π΅Π΄Π½ΠΈΡ
Π΄Π΅ΡΡΡΠΈΠ»Π΅ΡΠΈΠΉ ΠΏΡΠΈΠ²Π΅Π»Π° ΠΊ Π·Π°ΠΌΠ΅Π΄Π»Π΅Π½ΠΈΡ ΡΠ΅ΠΌΠΏΠΎΠ² ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ° Π² Π Π΅ΡΠΏΡΠ±Π»ΠΈΠΊΠ΅ ΠΡΠΌΠ΅Π½ΠΈΡ
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