Applicability of point dipoles approximation to all-dielectric metamaterials

All-dielectric metamaterials consisting of high-dielectric inclusions in a low-dielectric matrix are considered as a low-loss alternative to resonant metal-based metamaterials. In this contribution we investigate the applicability of the point electric and magnetic dipoles approximation to dielectric meta-atoms on the example of a dielectric ring metamaterial. Despite the large electrical size of high-dielectric meta-atoms, the dipole approximation allows for accurate prediction of the metamaterials properties for the rings with diameters up to ~0.8 of the lattice constant. The results provide important guidelines for design and optimization of all-dielectric metamaterials.Comment: 10 pages, 5 fugures, submitted to Physical Review

The effect of electron surface scattering on fine metal particle electromagnetic radiation absorption

The magnetic dipole absorption cross section of a spherically shaped metal particle was calculated in terms of kinetic approach. The particle considered was placed in the field of a plane electromagnetic wave. The model of boundary conditions was investigated taking into account the dependence of the reflectivity coefficient both on the surface roughness parameter and on the electron incidence angle. The results obtained were compared with theoretical computation results for a model of combined diffusion-specular boundary conditions of Fuchs.Comment: 9 pages, 5 figure

Tracing magnetic separators and their dependence on IMF clock angle in global magnetospheric simulations

A new, efficient, and highly accurate method for tracing magnetic separators in global magnetospheric simulations with arbitrary clock angle is presented. The technique is to begin at a magnetic null and iteratively march along the separator by finding where four magnetic topologies meet on a spherical surface. The technique is verified using exact solutions for separators resulting from an analytic magnetic field model that superposes dipolar and uniform magnetic fields. Global resistive magnetohydrodynamic simulations are performed using the three-dimensional BATS-R-US code with a uniform resistivity, in eight distinct simulations with interplanetary magnetic field (IMF) clock angles ranging from 0 (parallel) to 180 degrees (anti-parallel). Magnetic nulls and separators are found in the simulations, and it is shown that separators traced here are accurate for any clock angle, unlike the last closed field line on the Sun-Earth line that fails for southward IMF. Trends in magnetic null locations and the structure of magnetic separators as a function of clock angle are presented and compared with those from the analytic field model. There are many qualitative similarities between the two models, but quantitative differences are also noted. Dependence on solar wind density is briefly investigated.Comment: 10 pages, 10 figures, Presented at 2012 AGU Fall Meeting and 2013 Geospace Environment Modeling (GEM) Worksho

Determinant Line Bundles and Topological Invariants of Hyperbolic Geometry - Expository Remarks

We give some remarks on twisted determinant line bundles and Chern-Simons topological invariants associated with real hyperbolic manifolds. Index of a twisted Dirac operator is derived. We discuss briefly application of obtained results in topological quantum field theory.Comment: 10 pages. To appear in G@C, special issue devoted to QG, Unified Models and Strings, to mark 100th Anniversary of Tomsk State Pedagogical University. Editor - S.D. Odintso

Connective tissue dysplasia in patients with mitral valve prolapse.

Recently displasia of connective tissue is much spoken and written about. As a rule, these are scientific articles and reviews in which difficult terms prevail and doctors don't read them up to the end. And the problem, meanwhile, exists, and problem is very interesting. It is known that connective tissue consists of cells, fibers and intercellular substance. It is well known that it may be dense and loose and is widespread throughout the organism – skin, bones, cartilagle, vessels wall, stroma of bodies and even blood – at the basis of every element is connective tissue. The structure of connective tissue is well studied, and all biochemical structures are identified. Successes of molecular genetics allowed to define types, structure and localization of the genes which are responsible for synthesis of various elements. First of all we are interested in fibers of connective tissue – collagen with main function to maintain form, and the elastin, providing ability to reduction and relaxation. Dysplasia of connective tissue – the process genetically determined, i.e. at the basis of everything is mutations of the genes which are responsible for synthesis of fibers. Mutations may be the most various and in the most different genes. As a result of mutations collagen chains are formed incorrectly. Thus, they are shorter (deletion), or longer (insertion), they join not that amino acid (a dot mutation). So-called abnormal trimers of collagen appear, they don't maintain due mechanical loadings. The same is with elastin. The clinical picture will be defined by quantity and quality of mutations. Unfortunately, not only specific appearance and cosmetic defects belong to manifestations of dysplasia of connective tissue, but also heavy pathological changes of internal organs and the musculoskeletal apparatus