Transient Cherenkov radiation from an inhomogeneous string excited by an ultrashort laser pulse at superluminal velocity

An optical response of one-dimensional string made of dipoles with a periodically varying density excited by a spot of light moving along the string at the superluminal (sub-luminal) velocity is theoretically studied. The Cherenkov radiation in such system is rather unusual, possessing both transient and resonant character. We show that under certain conditions, in addition to the resonant Cherenkov peak another Doppler-like frequency appears in the radiation spectrum. Both linear (small-signal) and nonlinear regimes as well as different string topologies are considered.Comment: accepted to Phys. Rev.

Experiments on Sonoluminescence: Possible Nuclear and QED Aspects and Optical Applications

Experiments aimed at testing some hypothesis about the nature of Single Bubble Sonoluminescence are discussed. A possibility to search for micro-traces of thermonuclear neutrons is analyzed, with the aid of original low-background neutron counter operating under conditions of the deep shielding from Cosmic and other sources of background. Besides, some signatures of QED-contribution to the light emission in SBSL are under the consideration, as well as new approaches to probe a temperature inside the bubble. An applied-physics portion of the program is presented also, in which an attention is being paid to single- and a few-pulse light sources on the basis of SBSL.Comment: 4 pages; to be published by AIP in the Proc. ISNA-1

Modeling the burnout of solid polydisperse fuel under the conditions of external heat transfer

A self-similar burnout mode of solid polydisperse fuel is considered taking into consideration heat transfer between fuel particles, gases, and combustion chamber walls. A polydisperse composition of fuel is taken into account by introducing particle distribution functions by radiuses obtained for the kinetic and diffusion combustion modes. Equations for calculating the temperatures of particles and gases are presented, which are written for particles average with respect to their distribution functions by radiuses taking into account the fuel burnout ratio. The proposed equations take into consideration the influence of fuel composition, air excess factor, and gas recirculation ratio. Calculated graphs depicting the variation of particle and gas temperatures, and the fuel burnout ratio are presented for an anthracite-fired boiler. © 2013 Pleiades Publishing, Inc

Growth and optical properties of dye films and dye-in-polymer matrix deposited by vacuum evaporation

Searching new more effective materials for organic electroluminescent displays is continuing. The polymethine dyes is a class of organic materials that are very interesting for these purposes. Films of the polymethine dyes were deposited by evaporation in vacuum. Also deposited were dye-filled polytetrafluoroethylene (PTFE) films. Kinetics of growth and heating the films were observed using optical spectroscopy in situ. It was found out the influence of the chemical structure of dyes on growth and heating kinetics of the dye films. It was found that PTFE matrix strongly enhances dye stability

Short-Wave Excitations in Non-Local Gross-Pitaevskii Model

It is shown, that a non-local form of the Gross-Pitaevskii equation allows to describe not only the long-wave excitations, but also the short-wave ones in the systems with Bose-condensate. At given parameter values, the excitation spectrum mimics the Landau spectrum of quasi-particle excitations in superfluid Helium with roton minimum. The excitation wavelength, at which the roton minimum exists, is close to the inter-particle interaction range. It is shown, that the existence domain of the spectrum with a roton minimum is reduced, if one accounts for an inter-particle attraction.Comment: 5 pages, 5 figures, UJP style; presented at Bogolyubov Kyiv Conference "Modern Problems of Theoretical and Mathematical Physics", September 15-18, 200

Evaluation of the structural-phase characteristics of a supersaturated ultrafine-grained Au-Co solid solution by diffractometry in hard synchrotron radiation

A synchrotron radiation study of immiscible Au-Co alloys obtained by consolidating a heterogeneous mixture of components and subsequent severe plastic deformation was performed. Namely, the estimates of the crystal lattice parameter, the average size of the coherent scattering regions and lattice strains in mechanically alloyed supersaturated solid solutions were made using obtained diffraction patterns and diffraction spectra. The effect of the temperature regime of deformation processing on the listed characteristics is shown, when the transition from cold deformation to cryogenic is carried out. © 2020 American Institute of Physics Inc. All rights reserved.The work was done at the shared research center SSTRC on the basis of the VEPP-4 - VEPP-2000 complex at BINP SB RAS, using equipment supported by project RFMEFI62119X0022. The SR XRD performed at the station "Diffractometry in the "hard" X-ray range" of the 4th synchrotron radiation channel of the VEPP-3 accelerator of the Siberian Center of Synchrotron and Terahertz Radiation of the Budker Institute of Nuclear Physics by Alexey I. Ancharov. Obtaining and deformation processing of the investigated materials were carried out on the basis of M.N. Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences, Yekaterinburg. The research was carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation (theme “Рressure” No. АААА-А18-118020190104-3), supported in part by RFBR (project No. 19-32-60039)

Bose-Einstein Condensation in the Relativistic Pion Gas: Thermodynamic Limit and Finite Size Effects

We consider the Bose-Einstein condensation (BEC) in a relativistic pion gas. The thermodynamic limit when the system volume $V$ goes to infinity as well as the role of finite size effects are studied. At $V\to \infty$ the scaled variance for particle number fluctuations, $\omega=/$, converges to finite values in the normal phase above the BEC temperature, $T>T_C$. It diverges as $\omega \propto V^{1/3}$ at the BEC line $T=T_C$, and $\omega \propto V$ at $T<T_C$ in a phase with the BE condensate. Possible experimental signals of the pion BEC in finite systems created in high energy proton-proton collisions are discussed

Механизмы развития антипсихотик-индуцированных метаболических нарушений: фармакогенетический аспект

Antipsychotics are the main drug group in the treatment of disorders of the schizophrenic spectrum. At the same time, this drug group requires long-term use, has a narrow therapeutic breadth and a large spectrum and high severity of undesirable drug reactions, the manifestation of which is largely determined by the patient’s genotype. In this connection, the severity of undesirable drug reactions in drugs of the first and second generation of antipsychotics is different. Atypical antipsychotics, unlike typical antipsychotics, have a significantly lower chance of causing extrapyramidal disorders, though they primarily induce metabolic side effects, consisting of significant weight changes, glucose metabolism dysregulation, and dyslipidemia. These unwanted drug reactions significantly reduce adherence to therapy and can lead to serious complications in the future. At the same time, experience with the use of atypical antipsychotics has shown that the severity of unwanted reactions differs within the group of atypical antipsychotics and, more importantly, even for one drug taken by different patients, is a variable index. The reason for this phenomenon lies is in the polymorphism of the pharmacokinetic and pharmacodynamic factors involved in the metabolism of atypical antipsychotics and the different chemical structure of the drugs. The study of the effect of various combinations of polymorphic variants of the pharmacokinetic and pharmacodynamics factors on the development of antipsychotic-induced metabolic disorders is a complex and high-priority task of personalized medicine. Антипсихотики являются основными лекарственными препаратами в терапии расстройств шизофренического спектра. Антипсихотические препараты требуют длительного применения, обладают узкой терапевтической широтой, большим спектром и выраженностью нежелательных лекарственных реакций, проявление которых во многом определяется генотипом пациента. Выраженность нежелательных лекарственных реакций у препаратов первой и второй генераций антипсихотиков различна.Применение атипичных антипсихотиков, в отличие от типичных, реже вызывает экстрапирамидные расстройства, но индуцирует, прежде всего, метаболические нарушения: изменение веса, дизрегуляцию метаболизма глюкозы, дислипидемию. Перечисленные нежелательные лекарственные реакции в значительной мере снижают приверженность пациентов к терапии и могут привести к серьезным осложнениям в дальнейшем. Клинический опыт применения антипсихотиков показал, что выраженность нежелательных реакций одного препарата, принимаемого различными пациентами, является вариабельным показателем в связи с полиморфизмом генов фармакокинетических и фармакодинамических факторов, задействованных в реализации фармакологического действия антипсихотиков. В связи с этим изучение влияния различных комбинаций полиморфных вариантов генов фармакокинетических и фармакодинамических факторов на развитие антипсихотик-индуцированных метаболических нарушений является приоритетной задачей персонализированной психиатрии.