Analysis of plasma instabilities and verification of the BOUT code for the Large Plasma Device

The properties of linear instabilities in the Large Plasma Device [W. Gekelman et al., Rev. Sci. Inst., 62, 2875 (1991)] are studied both through analytic calculations and solving numerically a system of linearized collisional plasma fluid equations using the 3D fluid code BOUT [M. Umansky et al., Contrib. Plasma Phys. 180, 887 (2009)], which has been successfully modified to treat cylindrical geometry. Instability drive from plasma pressure gradients and flows is considered, focusing on resistive drift waves, the Kelvin-Helmholtz and rotational interchange instabilities. A general linear dispersion relation for partially ionized collisional plasmas including these modes is derived and analyzed. For LAPD relevant profiles including strongly driven flows it is found that all three modes can have comparable growth rates and frequencies. Detailed comparison with solutions of the analytic dispersion relation demonstrates that BOUT accurately reproduces all characteristics of linear modes in this system.Comment: Published in Physics of Plasmas, 17, 102107 (2010

Importance of In-Plane Anisotropy in the Quasi Two-Dimensional Antiferromagnet BaNi2_{2}V2_{2}O8_{8}

The phase diagram of the quasi two-dimensional antiferromagnet BaNi$_{2}$V$_{2}$O$_{8}$ is studied by specific heat, thermal expansion, magnetostriction, and magnetization for magnetic fields applied perpendicular to $\mathbf{c}$. At $\mu_0H^{*}\simeq1.5$ T, a crossover to a high-field state, where $T_N(H)$ increases linearly, arises from a competition of intrinsic and field-induced in-plane anisotropies. The pressure dependences of $T_N$ and $H^{*}$ are interpreted using the picture of a pressure-induced in-plane anisotropy. Even at zero field and ambient pressure, in-plane anisotropy cannot be neglected, which implies deviations from pure Berezinskii-Kosterlitz-Thouless behavior.Comment: 4 pages, 4 figure

Ferromagnetism and Lattice Distortions in the Perovskite YTiO3_3

The thermodynamic properties of the ferromagnetic perovskite YTiO$_3$ are investigated by thermal expansion, magnetostriction, specific heat, and magnetization measurements. The low-temperature spin-wave contribution to the specific heat, as well as an Arrott plot of the magnetization in the vicinity of the Curie temperature $T_C\simeq27$ K, are consistent with a three-dimensional Heisenberg model of ferromagnetism. However, a magnetic contribution to the thermal expansion persists well above $T_C$, which contrasts with typical three-dimensional Heisenberg ferromagnets, as shown by a comparison with the corresponding model system EuS. The pressure dependences of $T_C$ and of the spontaneous moment $M_s$ are extracted using thermodynamic relationships. They indicate that ferromagnetism is strengthened by uniaxial pressures $\mathbf{p}\parallel \mathbf{a}$ and is weakened by uniaxial pressures $\mathbf{p}\parallel \mathbf{b},\mathbf{c}$ and hydrostatic pressure. Our results show that the distortion along the $a$- and $b$-axes is further increased by the magnetic transition, confirming that ferromagnetism is favored by a large GdFeO$_3$-type distortion. The c-axis results however do not fit into this simple picture, which may be explained by an additional magnetoelastic effect, possibly related to a Jahn-Teller distortion.Comment: 12 pages, 13 figure

Signatures of Electronic Correlations in Optical Properties of LaFeAsO1−x_{1-x}Fx_x

Spectroscopic ellipsometry is used to determine the dielectric function of the superconducting LaFeAsO$_{0.9}$F$_{0.1}$ ($T_c$ = 27 K) and undoped LaFeAsO polycrystalline samples in the wide range 0.01-6.5 eV at temperatures 10 $\leq T \leq$ 350 K. The free charge carrier response in both samples is heavily damped with the effective carrier density as low as 0.040$\pm$0.005 electrons per unit cell. The spectral weight transfer in the undoped LaFeAsO associated with opening of the pseudogap at about 0.65 eV is restricted at energies below 2 eV. The spectra of superconducting LaFeAsO$_{0.9}$F$_{0.1}$ reveal a significant transfer of the spectral weight to a broad optical band above 4 eV with increasing temperature. Our data may imply that the electronic states near the Fermi surface are strongly renormalized due to electron-phonon and/or electron-electron interactions.Comment: 4 pages, 4 figures, units in Fig.2 adde

STUDY OF THE INFLUENCE OF THE SELF-EVALUATION OF PHYSICAL QUALITIES AND TECHNICAL-TACTICAL AC-TIONS ON SELF-EFFICIENCY IN HANDBALL

A study of the influence of self-assessment of physical qualities and technical-tactical actions on self-efficacy in handball is presented. The leading influence of high self-esteem on increasing self-efficacy is noted. It is emphasized that the influence of self-assessment of physical qualities and technical-tactical actions on self-efficacy in handball has not been suf-ficiently studied. Some differences in self-esteem are revealed: prevalence in group 1 is understated, and in 2 - high adequate, and a small number of inflated. A positive correlation between self-assessment of physical quali-ties and technical-tactical actions in and self-efficacy of handball has been proved.Представлено исследование влияния самооценки физических качеств и технико-тактических действий на самоэффективность в гандболе. Отмечается ведущее влияние высокой самооценки на повышение самоэффективности. Подчеркивается, что влияние само-оценки физических качеств и технико-тактических действий на самоэффективность в гандболе еще недостаточно изучено. Выявлены определенные различия в самооценках: преобладание в 1 группе заниженных, а во 2 - высоких адекватных, а также небольшое количество завышенных. Доказана положительная корреляция между самооценкой физических качеств и технико-тактических действий и самоэффективностью в гандбол

Traumeel S – bioregulatory approach in the treatment of inflammation

Department of Research, Ukrainian Academy of Biological Medicine, Kiev, Ukraine, Department of Internal Medicine, Ukrainian Medical Dental Academy, Poltava, UkraineBackground: In the treatment of inflammation, the action of widely used non-steroidal anti-inflammatory drugs (NSAIDs) is directed mainly to inhibit the synthesis of proinflammatory mediators, cell migration and proliferation, as well as to stimulate the formation of anti-inflammatory agents. These effects allow to quickly and significantly limit the severe symptoms of acute inflammation and pain. However, at the same time, NSAIDs suppress the sanogenetic mechanism of inflammation. Absence of correction of pathogenetic mechanisms of inflammation can lead to chronic inflammation and development of its complications (cicatricial changes, adhesions, contractures, etc.). Also, nonselectivity of NSAIDs contributes to the development of known side effects. And inhibitors of cyclooxygenase 2, as it became known, with excess daily therapeutic dose also cause serious side effects. New possibilities for solving this problem have already been demonstrated by the bioregulatory approach and the complex bioregulatory medicines (BRMs) created on its principles. Conclusions: The complex bioregulatory action of the medicine Traumeel S allows to control and optimize the course of the inflammatory process wherever it is located and of any form. Its use contributes to the full completion of inflammation with the recovery of the structure and function of the tissue, reduces the risk of complications and chronic inflammation. Such characteristics, combined with good tolerability (absence of side effects characteristic to NSAIDs) make Traumeel S a simple and reliable assistant to a doctor of any specialty in the treatment of inflammatory diseases of different localization

Dipole-active optical phonons in YTiO_3: ellipsometry study and lattice-dynamics calculations

The anisotropic complex dielectric response was accurately extracted from spectroscopic ellipsometry measurements at phonon frequencies for the three principal crystallographic directions of an orthorhombic (Pbnm) YTiO_3 single crystal. We identify all twenty five infrared-active phonon modes allowed by symmetry, 7B_1u, 9B_2u, and 9B_3u, polarized along the c-, b-, and a-axis, respectively. From a classical dispersion analysis of the complex dielectric functions \tilde\epsilon(\omega) and their inverses -1/\tilde\epsilon(\omega) we define the resonant frequencies, widths, and oscillator strengths of the transverse (TO) and longitudinal (LO) phonon modes. We calculate eigenfrequencies and eigenvectors of B_1u, B_2u, and B_3u normal modes and suggest assignments of the TO phonon modes observed in our ellipsometry spectra by comparing their frequencies and oscillator strengths with those resulting from the present lattice-dynamics study. Based on these assignments, we estimate dynamical effective charges of the atoms in the YTiO_3 lattice. We find that, in general, the dynamical effective charges in YTiO_3 lattice are typical for a family of perovskite oxides. By contrast to a ferroelectric BaTiO_3, the dynamical effective charge of oxygen related to a displacement along the c-axis does not show the anomalously large value. At the same time, the dynamical effective charges of Y and ab-plane oxygen exhibit anisotropy, indicating strong hybridization along the a-axis.Comment: 8 pages, 7 figure