The Universal Scaling Exponents of Anisotropy in Turbulence and their Measurement

The scaling properties of correlation functions of non-scalar fields (constructed from velocity derivatives) in isotropic hydrodynamic turbulence are characterized by a set of universal exponents. It is explained that these exponents also characterize the rate of decay of the effects of anisotropic forcing in developed turbulence. This set has never been measured in either numerical or laboratory experiments. These exponents are important for the general theory of turbulence, but also for modeling anisotropic flows. We propose in this letter how to measure these exponents using existing data bases of direct numerical simulations and by designing new laboratory experiments.Comment: 10 pages, latex, no figures, online (html) version available at http://lvov.weizmann.ac.il/EXP/EXP.htm

The influence of surface defects on the pinhole formation in silicide thin film

The growth of the CoSi layer was considered within the framework of the grain boundary diffusion model. The time dependences of the temperature due to the exothermic reaction of silicide formation as well as the dependences of the CoSi layer thickness were calculated for various values of the reaction activation energy. It was shown that the heat release at high reaction velocities can lead to the considerable increase of the temperature up to melting of the silicide and covering Co layers. The model of pinhole formation in cobalt silicide films was proposed on the basis of local melting in the reaction area at crystal defects of the silicon surface

Resonances and O-curves in Hamiltonian systems

We investigate the problem of the existence of trajectories asymptotic to elliptic equilibria of Hamiltonian systems in the presence of resonances.Comment: 12 page

Noncompact SL(2,R) spin chain

We consider the integrable spin chain model - the noncompact SL(2,R) spin magnet. The spin operators are realized as the generators of the unitary principal series representation of the SL(2,R) group. In an explicit form, we construct R-matrix, the Baxter Q-operator and the transition kernel to the representation of the Separated Variables (SoV). The expressions for the energy and quasimomentum of the eigenstates in terms of the Baxter Q-operator are derived. The analytic properties of the eigenvalues of the Baxter operator as a function of the spectral parameter are established. Applying the diagrammatic approach, we calculate Sklyanin's integration measure in the separated variables and obtain the solution to the spectral problem for the model in terms of the eigenvalues of the Q-operator. We show that the transition kernel to the SoV representation is factorized into a product of certain operators each depending on a single separated variable.Comment: 29 pages, 12 figure

MxTiSe2 (M = Cr, Mn, Cu) electronic structure study by methods of resonant X-ray photoemission spectroscopy and X-Ray absorption spectroscopy

Electronic structure and chemical bonding in TiX2 (X=S, Se, Te), TMxTiSe2 (TM=Cr, Mn, Cu) and CrxTi1-xSe2 were studied by x-ray resonance photoemission and absorption spectroscopy. These methods are detected to be strong sensitive to chemical bonding. Charge transfer from the intercalated atoms to Ti 3d band is detected. Narrow Ti 3d and Cu 3d bands are observed under Fermi level in CuxTiSe2.Comment: 7 pages, 4 figeres, ISIC 16 conferenc

A imigração e a língua de acolhimento em Portugal: questões de identidade e integração

A imigração, a diversidade e a multiculturalidade estão cada vez mais presentes nas sociedades modernas e a gestão desta realidade representa um enorme desafio, tanto para as sociedades de acolhimento como para os próprios imigrantes. Esse desafio implica um processo de adaptação e integração que apenas pode funcionar havendo vontade e esforço de ambas as partes envolvidas. O país (sociedade) de acolhimento deve trabalhar no sentido de promover um ambiente onde nativos e imigrantes possam conviver pacificamente garantindo a todos o respeito por direitos e deveres, bem como pelas suas identidades. Quanto aos imigrantes, têm que se adaptar a uma nova vida e uma nova realidade longe dos seus países de origem, devendo também eles respeitar o meio em que se encontram e do qual passam a fazer parte, ao mesmo tempo que tentam preservar as suas identidades e os laços com o seu país de origem. É um processo que envolve muitas mudanças, particularmente para os imigrantes. O país, a sociedade, os costumes, a cultura, o clima, as crenças, a língua, etc, fazem parte de um conjunto de novas experiências e novas aprendizagens para o imigrante. Essas novas experiências trazidas pela imigração têm a potencialidade de gerar mudança identitária. Através de um estudo que pretendeu dar voz aos próprios imigrantes, procurei neste trabalho perceber se há realmente mudanças ao nível da identidade provocadas pelo processo de imigração e de que modo atuam alguns elementos nessa mudança e no processo de integração, nomeadamente a língua – língua materna e língua de acolhimento.Abstract: Immigration, diversity and multiculturalism are every day more present in the modern society and dealing with this reality represents a big challenge for both, host society and the immigrants. It requires a process of adaptation and integration that can only work if both parts are involved and willing to make things work. The host society must promote an environment where natives and immigrants can live together peacefully and also guarantee that all legal rights and obligations are respected as well as people’s identities. When it comes to the immigrants, they have to adapt to a new culture and environment, making sure they respect the society which they are now part of, and also try to preserve their identities and the bound with their own country and people. It's a process that involves many changes, more so to the immigrants. The nation, society, habits, culture, weather, beliefs, language, etc., are all new experiences to them. These integration and experiences could have the potential to generate identity changes. Through a study that wanted to listen to the immigrants opinions and experiences, I’ve tried to understand if there are actually changes in immigrants identities as a result of the migration process and how do some elements take place in that change, particularly the language - language from the host society and language from the origin country

Separation of variables for the quantum SL(2,R) spin chain

We construct representation of the Separated Variables (SoV) for the quantum SL(2,R) Heisenberg closed spin chain and obtain the integral representation for the eigenfunctions of the model. We calculate explicitly the Sklyanin measure defining the scalar product in the SoV representation and demonstrate that the language of Feynman diagrams is extremely useful in establishing various properties of the model. The kernel of the unitary transformation to the SoV representation is described by the same "pyramid diagram" as appeared before in the SoV representation for the SL(2,C) spin magnet. We argue that this kernel is given by the product of the Baxter Q-operators projected onto a special reference state.Comment: 26 pages, Latex style, 9 figures. References corrected, minor stylistic changes, version to be publishe

Structural Properties of the Nanocrystallized Magnetite of Different Syntheses

Transmission electron microscopy (TEM) with electronic diffraction and X-ray diffraction (XRD) was used to study structural features of nanosized magnetite Fe3O4, which was synthesized using polymeric matrices (polysaccharide chitosan, at alias). From the received data it was revealed that growth inhibition and size stabilization of Fe3O4 nanoparticles were strongly affected by polysaccharide matrix. It was also observed that directional size decrease of Fe3O4 nanoparticles was accompanied by the increasing defectiveness of crystal lattice and decreasing unit cell size. The effectiveness of complementary use of both TEM with electronic diffraction and XRD techniques for structural and substructural parameters determination while studying magnetite nanosized particles synthesized in polysaccharide matrices is shown in this paper. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545

Noncompact Heisenberg spin magnets from high-energy QCD: I. Baxter Q-operator and Separation of Variables

We analyze a completely integrable two-dimensional quantum-mechanical model that emerged in the recent studies of the compound gluonic states in multi-color QCD at high energy. The model represents a generalization of the well-known homogenous Heisenberg spin magnet to infinite-dimensional representations of the SL(2,C) group and can be reformulated within the Quantum Inverse Scattering Method. Solving the Yang-Baxter equation, we obtain the R-matrix for the SL(2,C) representations of the principal series and discuss its properties. We explicitly construct the Baxter Q-operator for this model and show how it can be used to determine the energy spectrum. We apply Sklyanin's method of the Separated Variables to obtain an integral representation for the eigenfunctions of the Hamiltonian. We demonstrate that the language of Feynman diagrams supplemented with the method of uniqueness provide a powerful technique for analyzing the properties of the model.Comment: 61 pages, 19 figures; version to appear in Nucl.Phys.

Structural Properties of the Nanocrystallized Magnetite of Different Syntheses

Transmission electron microscopy (TEM) with electronic diffraction and X-ray diffraction (XRD) was used to study structural features of nanosized magnetite Fe3O4, which was synthesized using polymeric matrices (polysaccharide chitosan, at alias). From the received data it was revealed that growth inhibition and size stabilization of Fe3O4 nanoparticles were strongly affected by polysaccharide matrix. It was also observed that directional size decrease of Fe3O4 nanoparticles was accompanied by the increasing defectiveness of crystal lattice and decreasing unit cell size. The effectiveness of complementary use of both TEM with electronic diffraction and XRD techniques for structural and substructural parameters determination while studying magnetite nanosized particles synthesized in polysaccharide matrices is shown in this paper. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545