269 research outputs found
Wightman function and Casimir densities for Robin plates in the Fulling-Rindler vacuum
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
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
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
The article deals with the problem of social justice in modern Russian societ
Sociocultural aspect of realization of civil control in modern Russian society
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
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 at
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
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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