September 2007 arXiv papers — page 49

O. Krupych, Ya. Dyachok, I. Smaga, R. Vlokh

The regularities of laser-induced damage of anisotropic materials, such as LiNbO3 and KDP dielectric single crystals, are experimentally studied. It is revealed that the shape of laser-induced damage in the dielectric crystals depends on the elastic symmetry of crystal and the propagation direction of the laser beam. When the beam propagates along the optic

Yu. P. Goncharov

On the basis of the confinement mechanism earlier proposed by author, the electric form factor of $η$-meson is nonperturbatively calculated. The latter is then applied to describe electromagnetic decay $η\to2γ$ which entails estimates for parameters of the confining SU(3)-gluonic field in $η$-meson. The corresponding estimates of the gluon concentrations, el

M K Suleymanov, O B Abdinov, R M Aliyev, F M Aliyev

We have analyzed the angular distributions of the b- particles emitted in Kr+Em -reaction at 0.95 A GeV and in Au+Em -reaction at 10.7 A GeV and compared these with lighter projectile experiments for which some structure in the angular distribution of slow particles was observed. The same structure for the b-particles almost disappears by increasing the proj

O. Kushnir, P. Nek, R. Vlokh, N. Kukhtarev

Using the Jones matrix formalism, crystal optical properties of inhomogeneous material consisting of a pile of weakly birefringent plates are analysed in relation to the cell model adopted in polarization tomography of 3D dielectric tensor field in photoelastic media. It is shown that the material manifests in general an "apparent" optical gyration c

I. Martynyuk-Lototska, O. Mys, Ya. Dyachok, T. Dudok

Photoelastic coefficients of beta-BaB2O4 and Li2B4O7 crystals are calculated on the basis of piezooptic measurements performed with interferometric technique and the elastic compliance and stiffness data. Using the experimental results, the acoustooptic (AO) figure of merit (FM) has been estimated for the possible geometries of AO interaction. It is shown th

R. Vlokh, I. Girnyk, O. V. Vlokh, I. Skab

The domain structure in K2Cd2xMn2(1-x)(SO4)3 (x=0.5, 0.7 and 0.9) langbeinite crystals is studied with the aid of optical polarization microscopy. It is shown that the domain walls in ferro-elastic langbeinites separate enantiomorphous orientation states. These orientation states appear in the phase with the symmetry 23 in connection with the hypothetic phas

I. Martynyuk-Lototska, T. Dudok, Ya. Dyachok, Ya. Burak

Basing on the measurements of photoelastic coefficients, acoustic waves velocities and the refractive indices, the possible geometries for acoustooptic interaction in b-BaB2O4 crystals have been analysed. It has been shown that the acoustooptic figure of merit achieves its maximum value when the transverse acoustic wave v13 with the velocity 817m/s is propag

I. Girnyk, O. Krupych, I. Martunyuk-Lototska, F. Motsnyi

The results for dilatometric, ultrasonic velocity and the domain struct-ure studies of Cs3Bi2I9 crystals in the course of ferroelastic phase trans-ition are presented. It is shown that the phase transition in Cs3Bi2I9 is of the first order. Basing on the thermal expansion results and the data obtained for the elastic stiffness of Cs3Bi2I9 crystals, the laten

R. Vlokh, O. Mys, M. Kostyrko

The results of study of piezoelectrooptic (PEO) effect in the course of ferroelectric-ferroelastic phase transition in Rochelle salt crystals are presented. The coefficient of the combined effect is obtained from measurements of the changes in the electrooptic coefficients under the action of mechanical stress and the changes in the piezooptic coefficients u

O. Mys, V. Adamiv, I. Martunyuk-Lototska, R. Vlokh

Electrooptic coefficient of CsLiB6O10 crystals has been experimentally determined as r63=3.3*10-12m/V. The half-wave voltage for CsLiB6O10 (Ul/2=26 kV) is three orders of magnitude larger than that of the known KDP crystals.

O. Mys, R. Vlokh

In the present paper the coefficients of piezooptic (PO), electrooptic (EO) and combined piezoelectrooptic (PEO) effects for LiNbO3 and LiTaO3 crystals are reported. It is shown that the combined PEO effect is interchangeable, i.e. its coefficients determined independ-ently from the EO and PO experiments are the same.

Agnieszka Figaj, Tomasz Luczak

We find the asymptotic value of the Ramsey number for a triple of long cycles, where the lengths of the cycles are large but may have different parity.

L. J. Goicoechea, V. N. Shalyapin, E. Koptelova, R. Gil-Merino

To go into the details about the variability of the double quasar SBS 0909+532, we designed a monitoring programme with the 2 m Liverpool Robotic Telescope in the r Sloan filter, spanning 1.5 years from 2005 January to 2006 June. The r-band light curves of the A and B components, several cross-correlation techniques and a large number of simulations (synthet

Thomas Rauch, Klaus Werner, Marc Ziegler, Jeffrey W. Kruk

Spectral analysis by means of NLTE model atmospheres has presently arrived at a high level of sophistication. High-resolution spectra of central stars of planetary nebulae can be reproduced in detail from the infrared to the X-ray wavelength range. In the case of LSV +4621, the exciting star of Sh 2-216, we demonstrate the state-of-the-art in the determinati

V. S. Pandey, B. N. Dwivedi

We comment on the work by Chandra and Kumthekar (2007, henceforth CK) which is questionable. In the derivation of dispersion relation, CK neither invoke the concept of vector space nor do they follow the basic criterion for the elimination of perturbation terms under which the damped magnetoacoustic waves are derived.

M. Gmitra, J. Barnas

Spin-transfer torque in asymmetric spin valves can destabilize both parallel and antiparallel configurations and can lead to precessional modes also in the absence of an external magnetic field. We find a bistable precessional regime in such systems and show that thermal fluctuations can excite transitions (telegraph noise) between the corresponding oscillat

E. Comay

This work points out an application of the regular theory of charge-monopole electrodynamics to the new experiments of very high energy. Using this theory, it is explained why the new regions of high energy interactions that will be explored by CERN's Large Hadron Collider may show a significant increase of the cross section. This conclusion illustrates

Victor Katsnelson

For a convex set (K) of the (n)-dimensional Euclidean space, the Steiner-Minkowski polynomial (M_K(t)) is defined as the (n)-dimensional Euclidean volume of the neighborhood of the radius (t). Being defined for positive (t), the Steiner-Minkowski polynomials are considered for all complex (t). The renormalization procedure for Steiner polynomial is proposed.

Mahmoud Taherzadeh, Amir K. Khandani

In this paper, the inherent drawbacks of the naive lattice decoding for MIMO fading systems is investigated. We show that using the naive lattice decoding for MIMO systems has considerable deficiencies in terms of the rate-diversity trade-off. Unlike the case of maximum-likelihood decoding, in this case, even the perfect lattice space-time codes which have t

Lei Wang, Baowen Li

Logic gates are basic digital elements for computers. We build up thermal logic gates that can perform similar operations as their electronic counterparts. The thermal logic gates are based on the nonlinear lattices, which exhibit very intriguing phenomena due to their temperature dependent power spectra. We demonstrate that phonons, the heat carriers, can b

P. A. Bhobe, K. R. Priolkar, P. R. Sarode

Heusler alloys that undergo martensitic transformation in ferromagnetic state are of increasing scientific and technological interest. These alloys show large magnetic field induced strains upon martensitic phase change thus making it a potential candidate for magneto-mechanical actuation. The crystal structure of martensite is an important factor that affec

Judith G. Cohen, Norbert Christlieb, Andrew McWilliam, Stephen Shectman

We present a detailed abundance analysis based on high resolution and high signal-to-noise spectra of eight extremely metal poor (EMP) stars with [Fe/H] < -3.5$ dex, four of which are new. Only stars with 4900 < Teff< 5650 K are included. Two stars of the eight are outliers in each of several abundance ratios. The most metal poor star in this sample, HE1424-

P Ao

I reason here that the known folk law in biology that there is no general law in biology because of exceptions is false. The (quantitative) systems biology offers the potential to solve the Borges Dilemma, by transcending it. There have already a plenty of indications on this trend.

Vladan Pankovic, Nikola Vunduk, Milan Predojevic

In this work we suggest a simple mathematical model for the dynamics of the population of children and adolescents without problematic behavior (criminal activities etc.). This model represents a typical population growth equation but with time dependent (linearly decreasing) population growth coefficient. Given equation admits definition of the half-life ti