Modern technologies of digital economy as a catalyst for economic growth of regional markets of the Russian Federation

This article contains a conceptual framework that discloses the concept of the digital economy as a set of economic relations, which are mediated by information and computer technologies used by all participants in the socio-economic syste

The system of EAS time analysis

The extensive air showers' (EAS) front shape, angle of incidence, disk thickness, particle distribution along the shower, on the delayed and EAS front advancing particles were determined. The suggested system of the EAS time analysis allows determination of the whole EAS longitudinal structure at the observation points. The information from the detectors is continuously recorded in the memory with the memory cell switching in 5 ns, this enables fixation of the moment of pulse input from the detector with an accuracy to + or - 2.5 ns. Along with the fast memory, a slow memory with the cell switching in 1 micron s is introduced in the system, this permits observation of relatively large time intervals with respect to the trigger pulse with an appropriately lower accuracy

Resonant finite-size impurities in graphene, unitary limit and Friedel oscillations

Unitary limit for model point scatterers in graphene is known to reveal low-energy resonances. The same limit could be achieved from hybridization of band electrons with the localized impurity level positioned in the vicinity of the Fermi level. The finite size defects represent an easier realization of the effective unitary limit, occurring when the Fermi wavelength induced by the potential becomes of the order of the size of the defect. We calculate the induced electron density and find two signatures of a strong impurity, independent of its specific realization. The dependence of the impurity-induced electron density on the distance changes near resonances from ~r^{-3} to ~r^{-2}. The total number of induced particles at the resonance is equal to one per degree of spin and valley degeneracy. The effects of doping on the induced density are found.Comment: 8 pages, 3 figures, published versio

Combating Gender-Biased Sex Selection in Armenia

UID/CPO/04627/2013publishersversionpublishe

Wightman function and vacuum densities for a Z_2-symmetric thick brane in AdS spacetime

Positive frequency Wightman function, vacuum expectation values of the field square and the energy-momentum tensor induced by a Z_{2}-symmetric brane with finite thickness located on (D+1)- dimensional AdS background are evaluated for a massive scalar field with general curvature coupling parameter. For the general case of static plane symmetric interior structure the expectation values in the region outside the brane are presented as the sum of free AdS and brane induced parts. For a conformally coupled massless scalar the brane induced part in the vacuum energy-momentum tensor vanishes. In the limit of strong gravitational fields the brane induced parts are exponentially suppressed for points not too close to the brane boundary. As an application of general results a special model is considered in which the geometry inside the brane is a slice of the Minkowski spacetime orbifolded along the direction perpendicular to the brane. For this model the Wightman function, vacuum expectation values of the field square and the energy-momentum tensor inside the brane are evaluated as well and their behavior is discussed in various asymptotic regions of the parameters. It is shown that for both minimally and conformally coupled scalar fields the interior vacuum forces acting on the brane boundaries tend to decrease the brane thickness.Comment: 25 pages, 6 figures, discussion adde

Vacuum densities for a thick brane in AdS spacetime

For a massive scalar field with general curvature coupling parameter we evaluate Wightman function, vacuum expectation values of the field square and the energy-momentum tensor induced by a $Z_{2}$-symmetric brane with finite thickness located on $(D+1)$-dimensional AdS bulk. For the general case of static plane symmetric interior structure the expectation values in the region outside the brane are presented as the sum of free AdS and brane induced parts. For a conformally coupled massless scalar the brane induced part in the vacuum energy-momentum tensor vanishes. In the limit of strong gravitational fields the brane induced parts are exponentially suppressed for points not too close to the brane boundary. As an application of general results a special model is considered in which the geometry inside the brane is a slice of the Minkowski spacetime orbifolded along the direction perpendicular to the brane. For this model the Wightman function, vacuum expectation values of the field square and the energy-momentum tensor inside the brane are evaluated. It is shown that for both minimally and conformally coupled scalar fields the interior vacuum forces acting on the brane boundaries tend to decrease the brane thickness.Comment: 12 pages, 2 figures, talk presented at QFEXT07, Leipzig, September 17-21, 200

One-dimensional plasmons confined in bilayer graphene p-n junctions

Gapless spectrum of graphene allows easy spatial separation of electrons and holes with an external in-plane electric field. Guided collective plasmon modes can propagate along the separation line, whose amplitude decays with the distance to it. Their spectrum and direction of propagation can be controlled with the strength and direction of in-plane electric field. In case of a bilayer graphene additional control is possible by the perpendicular electric field that opens a gap in the band spectrum of electrons. We investigate guided plasmon spectra in bilayer p-n junctions using hydrodynamics of charged electron liquid.Comment: published version, minor change

2D skew scattering in the vicinity and away from resonant scattering condition

We studied the energy dependence of the 2D skew scattering from strong potential, for which the Born approximation is not applicable. Since the skew scattering cross section is zero both at low and at high energies, it exhibits a maximum as a function of energy of incident electron. We found analytically the shape of the maximum for an exactly solvable model of circular-barrier potential. Within a rescaling factor, this shape is universal for strong potentials. If the repulsive potential has an attractive core, the discrete levels of the core become quasilocal due to degeneracy with continuum. For energy of incident electron close to the quasilocal state with zero angular momentum, the enhancement of the net cross section is accompanied by resonant enhancement of the skew scattering. By contrast, near the resonance with quasilocal states having momenta $\pm 1$, the skew scattering cross section is an odd function of energy deviation from the resonance, and passes through zero, i.e., it exhibits a sign reversal. In the latter case, in the presence of the Fermi sea, the Kondo resonance manifests itself in strong temperature dependence of the skew scattering.Comment: 9 pages, 5 figure

Cognitive status in older patients with limited mobility as a predictor of negative outcome

Background. Cognitive impairment (CI) is one of the important disability factors in the elderly. The role of CI in prognosis of the frailest patients with limited mobility is uncertain.The aim. To determine the influence of the initial cognitive status in the group of patronage patients aged 60 years and older on the risk of mortality within one year.Materials and methods. Study group consisted of 450 patients from patronage group with one-year period of observation (from July 2019 till July 2020). Initial physical, functional, neuropsychiatriac and social statuses were evaluated by comprehensive geriatric assessment. Cognitive impairment was screened by Mini-Mental State Examination (MMSE), with dividing patients into dementia group (MMSE ≤ 24) and no-dementia group (MMSE > 24). The mortality rate after one year was assessed.Results. Of the 450 patients included in the study, dementia was present in 44.2 %. Patients with dementia were more prone to greater severity of chronic pain, sleep disturbances, depression, malnutrition and anemia. After one year of observation 34 out of 196 patients (17.3 %) in the group of patients with dementia and 18 out of 248 patients (7.3 %; p = 0.002) in the no-dementia group died. According to multivariate analysis, independent risk factors for death in patients with dementia were anemia, hearing impairment and a history of bone fractures.Conclusion. Thus, the assessment of the cognitive status of frail patients with limited mobility is important for the purpose of identifying the most vulnerable individuals with a high risk of adverse outcomes

Застосування теорії самоорганізації с-простору для багатокритеріальної оптимізації складних систем.

Пропонується аксіоматична хвильова модель С-простору, описуються основні положення теорії самоорганізації, розглядаються можливості її застосування для оптимізації систем