269 research outputs found

    Wightman function and Casimir densities for Robin plates in the Fulling-Rindler vacuum

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    Wightman function, the vacuum expectation values of the field square and the energy-momentum tensor are investigated for a massive scalar field with an arbitrary curvature coupling parameter in the region between two infinite parallel plates moving by uniform proper acceleration. We assume that the field is prepared in the Fulling-Rindler vacuum state and satisfies Robin boundary conditions on the plates. The mode-summation method is used with a combination of a variant of the generalized Abel-Plana formula. This allows to extract manifestly the contributions to the expectation values due to a single boundary and to present the second plate-induced parts in terms of exponentially convergent integrals. Various limiting cases are investigated. The vacuum forces acting on the boundaries are presented as a sum of the self-action and 'interaction' terms. The first one contains well known surface divergences and needs a further renormalization. The 'interaction' forces between the plates are investigated as functions of the proper accelerations and coefficients in the boundary conditions. We show that there is a region in the space of these parameters in which the 'interaction' forces are repulsive for small distances and attractive for large distances.Comment: 20 pages, 2 figures, discussion added, accepted for publication in Int. J. Mod. Phys.

    Consolidation potential of the value of justice in implementation of civilian control over the performance of authorities in the contemporary Russian society

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    The article considers the social justice as one of the fundamental values of modern Russian society. It is stressed that justice in Russian history is one of the most significant motivators to essentially civil action due primarily to a sociocultural specificity of Russia where the controlling exposure historically in the absolute majority of cases was based on the appeal to the values of justice and not to the law, which is not typical for Western culture. It is noted that social justice is a value, i.e. a reality of social and individual life. Social justice as a value includes a gnoseological, regulatory, measurement and ideal components. Being at the most critical crossover point between individual and public interests, it is a historically and culturally acceptable measure of equality and liberty of individuals. Based on data of sociological surveys, the authors analyzed the insights of Russian people into social justic

    Polarization-Tailored Raman Frequency Conversion in Chiral Gas-Filled Hollow Core Photonic Crystal Fibers

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    Broadband-tunable sources of circularly-polarized light are crucial in fields such as laser science, biomedicine and spectroscopy. Conventional sources rely on nonlinear wavelength conversion and polarization control using standard optical components, and are limited by the availability of suitably transparent crystals and glasses. Although gas-filled hollow-core photonic crystal fiber provides pressure-tunable dispersion, long well-controlled optical path-lengths, and high Raman conversion efficiency, it is unable to preserve circular polarization state, typically exhibiting weak linear birefringence. Here we report a revolutionary approach based on helically-twisted hollow-core photonic crystal fiber, which displays circular birefringence, thus robustly maintaining circular polarization state against external perturbations. This makes it possible to generate pure circularly-polarized Stokes and anti-Stokes signals by rotational Raman scattering in hydrogen. The polarization state of the frequency-shifted Raman bands can be continuously varied by tuning the gas pressure in the vicinity of the gain suppression point. The results pave the way to a new generation of compact and efficient fiber-based sources of broadband light with fully-controllable polarization state.Comment: 5 pages, 4 figure

    Value of justice as the basis for building consolidation of the population in modern Russia

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    The article deals with the problem of social justice in modern Russian societ

    Sociocultural aspect of realization of civil control in modern Russian society

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    The backwardness of civil control in modern Russia is connected with a complex of the reasons of sociocultural character, including with specifics of the Russian traditions of public participation. It is proved that only collective forms of civil control relying on mobilization and use of the social capital of local communities can be the most effective in Russi

    Controlling Stray Electric Fields on an Atom Chip for Rydberg Experiments

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    Experiments handling Rydberg atoms near surfaces must necessarily deal with the high sensitivity of Rydberg atoms to (stray) electric fields that typically emanate from adsorbates on the surface. We demonstrate a method to modify and reduce the stray electric field by changing the adsorbates distribution. We use one of the Rydberg excitation lasers to locally affect the adsorbed dipole distribution. By adjusting the averaged exposure time we change the strength (with the minimal value less than 0.2V/cm0.2\,\textrm{V/cm} at 78μm78\,\mu\textrm{m} from the chip) and even the sign of the perpendicular field component. This technique is a useful tool for experiments handling Ryberg atoms near surfaces, including atom chips

    Clinical efficacy of a personalized exercise program in the rehabilitation of patients with atrial fibrillation after radiofrequency ablation

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    Aim. To study the clinical efficacy and safety of a personalized exercise program in the rehabilitation of patients with paroxysmal atrial fibrillation (AF) after primary pulmonary vein radiofrequency ablation (RFA).Material and methods. Patients (n=48) with paroxysmal AF who underwent RFA were randomized into two groups: main (n=24) — patients involved in the exercise program and received standard therapy; control (n=24) — patients received standard therapy. The program included exercise complexes with the calculation of energy consumption, step training and walking. The program lasted 6 months, while the follow-up period — 12 months. All patients in the study underwent a faceto-face learning interview.Results. After 6-month exercise program, bicycle ergometer test revealed an increase in duration (by 18,6%, p<0,001) and power (by 24,8%, p<0,01) of the load, while these changes were not revealed in the control group. The positive aftereffect of training on these parameters persisted even after the completion of program. Left atrial and left ventricular end-diastolic dimension remained stable in exercise program group and significantly increased in the control group. In contrast to the control group, the following parameters significantly decreased in trained patients after 6 months: body mass index by 2,8% (p<0,05), systolic blood pressure by 2,1% (p<0,05), heart rate by 12,1% (p<0,05), low-density lipoprotein cholesterol concentration by 18,8% (p<0,001), high-sensitivity C-reactive protein by 22,9% (p<0,05), N-terminal pro-brain natriuretic peptide by 28,2% ( p<0,05), aldosterone by 41,5% (p<0,001) and angiotensin II by 41,3%, p<0,05). In addition, in the exercise program group an increase in high-density lipoprotein cholesterol by 20,6% (p<0,05) and physical activity level by 23,8% (p=0,001) was revealed. At the same time, both groups showed a significant decrease in the concentration of fibrinogen and transforming growth factor-β1. After 6 months, in the exercise program group versus the control group, there was a decrease in the number of registered supraventricular premature beats (p<0,01), episodes of supraventricular tachyarrhythmia (p<0,05), including AF (p<0,05).Conclusion. Involvement of patients with AF after catheter RFA in a cardiac rehabilitation program based on moderate-intensity aerobic training improves exercise tolerance, cardiac function, corrects thrombogenic factors, and reduces the likelihood of arrhythmia recurrence, including AF
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