LC nanocomposites: induced optical singularities, managed nano/micro structure, and electrical conductivity

Microstructure, phase transitions, electrical conductivity, and optical and electrooptical properties of multiwalled carbon nanotubes (NTs), dispersed in the cholesteric liquid crystal (cholesteryl oleyl carbonate, COC), nematic 5CB and their mixtures, were studied in the temperature range between 255 K and 363 K. The relative concentration X=COC/(COC+5CB)was varied within 0.0-1.0. The concentration $C_p$ of NTs was varied within 0.01-5% wt. The value of X affected agglomeration and stability of NTs inside COC+5CB. High-quality dispersion, exfoliation, and stabilization of the NTs were observed in COC solvent ("good" solvent). From the other side, the aggregation of NTs was very pronounced in nematic 5CB solvent ("bad" solvent). The dispersing quality of solvent influenced the percolation concentration $C_p$, corresponding to transition between the low conductive and high conductive states: e.g., percolation was observed at $C_p=1$ and $C_p=0.1$ for pure COC and 5CB, respectively. The effects of thermal pre-history on the heating-cooling hysteretic behavior of electrical conductivity were studied. The mechanism of dispersion of NTs in COC+5CB mixtures is discussed. Utilization of the mixtures of "good" and "bad" solvents allowed fine regulation of the dispersion, stability and electrical conductivity of LC+NTs composites. The mixtures of COC and 5CB were found to be promising for application as functional media with controllable useful chiral and electrophysical properties.Comment: 10 pages, 9 figure

Identification of new cataclysmic variables in the 1RXS and USNO-B1.0 catalogs

As a result of applying the original optical variability search method on publicly available data, we have found eight new cataclysmic variables and two possible Optically Violent Variable quasars among the previously unidentified X-ray sources in the ROSAT catalog. We describe the search method and present the characteristics of the newly identified variable stars. The obtained results demonstrate the large potential of the concept of Virtual Observatory for identifying new objects of astrophysical interest.Comment: 16 pages, 11 figures, 2 tables; submitted to Astronomy Letter

Comparative legal analysis of mediation in Russia and the EU

The purpose of this article is to identify the specifics of mediation procedures, review them as extrajudicial method of conflict resolution. As the methodological basis of the research we use the synergistic, phenomenological and dialectical analysis techniques to examine the main aspects of the mediation as well as identify its principal features. As a result of the study, the authors concluded that in Russia it is necessary to take into account the international experience of mediation, legislation to support the mediation process and in some cases give it forceful character, to develop cooperation with the courts and notaries with the mediators.peer-reviewe

Optical polarization observations with the MASTER robotic net

We present results of optical polarization observations performed with the MASTER robotic net for three types of objects: gamma-ray bursts, supernovae, and blazars. For the Swift gamma-ray bursts GRB100906A, GRB110422A, GRB121011A, polarization observations were obtained during very early stages of optical emission. For GRB100906A it was the first prompt optical polarization observation in the world. Photometry in polarizers is presented for Type Ia Supernova 2012bh during 20 days, starting on March 27, 2012. We find that the linear polarization of SN 2012bh at the early stage of the envelope expansion was less than 3%. Polarization measurements for the blazars OC 457, 3C 454.3, QSO B1215+303, 87GB 165943.2+395846 at single nights are presented. We infer the degree of the linear polarization and polarization angle. The blazars OC 457 and 3C 454.3 were observed during their periods of activity. The results show that MASTER is able to measure substantially polarized light; at the same time it is not suitable for determining weak polarization (less than 5%) of dim objects (fainter than 16$^m$). Polarimetric observations of the optical emission from gamma-ray bursts and supernovae are necessary to investigate the nature of these transient objects.Comment: 31 pages, 12 figures, 4 tables; Exposure times in Table 2 have been correcte

Muon pair creation from positronium in a circularly polarized laser field

We study elementary particle reactions that result from the interaction of an atomic system with a very intense laser wave of circular polarization. As a specific example, we calculate the rate for the laser-driven reaction $e^+e^- \to \mu^+\mu^-$, where the electron and positron originate from a positronium atom or, alternatively, from a nonrelativistic $e^+e^-$ plasma. We distinguish accordingly between the coherent and incoherent channels of the process. Apart from numerical calculations, we derive by analytical means compact formulas for the corresponding reaction rates. The rate for the coherent channel in a laser field of circular polarization is shown to be damped because of the destructive interference of the partial waves that constitute the positronium ground-state wave packet. Conditions for the observation of the process via the dominant incoherent channel in a circularly polarized field are pointed out

Trends in the formation of the ovarian follicular reserve

This review describes folliculogenesis from the formation of a primordial follicle around the oocyte during the diplotene stage of prophase of meiosis I to that of a preovulatory follicle, maturation of an oocyte, and transformation of its chromosomal nucleolus complex into the karyosphere. It briefly highlights literature disagreements on the terminology of ovarian follicular reserve and folliculogenesis. The possibilities of evaluating the ovarian follicular system are given

Integrated Training Based on Information and Communication Technologies in the Practice of Teaching Russian language, Literature and Cultural Studies to Foreign Bilingual Students of Non-philological Specialties

The article presents an innovative method of teaching foreign bilingual students of nonphilological specialties (engineering, physics and mathematics, and natural science profiles of the RUDN University). The authors develop a teaching manual “Russian Literature on the Screen” which follows the principle of integrated learning (involving focusing students’ attention on interdisciplinary connections and replenishing their knowledge of Russian literature, culture, and history in the process of teaching Russian as a foreign language) and allows using information and communication technologies in the educational process

Mathematical Modeling of the Impact Produced by Magnetic Disks on Living Cells

An analytical solution of the problem on elastic deformation of a membrane allows analyzing deformation of typical living cells under the influence of magnetic disks attached to the cells. Based on the numerical solution of two-dimensional elliptic boundary value problems, the magnetic polarizabilities of the disks are obtained as the functions of magnetic permeability of the disk substance. It is shown that typical thin disks made of iron, nickel and cobalt in the mode far from saturation are magnetized substantially the same as a disk with infinite magnetic permeability. Though the solved problems are stationary, the results are also usable in the analysis of quasi-stationary processes such as low-frequency variation of external magnetic field

Polyunsaturated fatty acid status of leukocyte membranes in COPD patients

The aim of the study was to analyze n-3 and n-6 polyunsaturated fatty acid (PUFA) profile of blood leukocyte cytomembranes in mild and moderate COPD, and to establish possible role of these fatty acids in COPD progression. The study involved 110 patients with mild disease (n = 60) and moderate COPD (50 patients), at average age of 57.5±4.8 years old. The control group consisted of 32 practically healthy non-smoking people with normal pulmonary function (average age 42.0±3.4 years). The immunological study included flow cytometric determination of blood immune cell subpopulations, i.e., T lymphocytes (CD3+), T helper cells (CD4+), cytotoxic T lymphocytes (CD8+), and B cells (CD19+) using Becton Dickinson machine (USA). Fatty acid methyl esters redissolved in hexane were analyzed using “Shimadzu GC-2010” gas-liquid chromato-graphic system (Japan). Analysis of the polyunsaturated fatty acid profile of leukocyte membranes in COPD patients revealed a reduced concentration of essential linoleic acid (18:2n-6) regardless of the disease severity. The leukocyte membrane levels of the long-chain n-6 PUFAs, such as dihomo-γ-linolenic acid (20:3n-6), arachidonic acid (20:4n-6), and docosatetraenoic acid (22:4n-6), were elevated in patients with COPD compared with the control group. However, the concentration of the described above n-6 PUFAs in leukocyte membranes was increased in patients with moderate COPD compared to the patients with mild COPD. The significant deficiency of a physiologically important n-3 PUFA, eicosapentaenoic acid (20:5n- 3), in leukocyte membranes in the COPD patients was revealed. In turn, the low level of 20:5n-3 could result from the deficiency of its precursor, docosahexaenoic acid (22:6n-3). The results of the study indicate the modification in the PUFA composition of blood leukocyte membranes in the patients with COPD. It was shown that altered composition of long-chain fatty acid of leukocyte membranes emerges already at the early stage of the disease. Therefore, the imbalance in fatty acids composition of leukocytes makes a significant contribution to the development and the progression of COPD