Simferopol', Ukraine

Taurida National University

www.crimea.edu
Simferopol', Ukraine
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Grant
Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: ENV.2008.4.1.4.1. | Award Amount: 8.01M | Year: 2009

The Black Sea Catchment is internationally known as one of ecologically unsustainable development and inadequate resource management, which has led to severe environmental, social and economic problems. EnviroGRIDS @ Black Sea Catchment aims at building the capacities of regional stakeholders to use new international standards to gather, store, distribute, analyze, visualize and disseminate crucial information on past, present and future states of the environment, in order to assess its sustainability and vulnerability. The EnviroGRIDS @ Black Sea Catchment project addresses these issues by bringing several emerging information technologies that are revolutionizing the way we are able to observe our planet. The Group on Earth Observation Systems of Systems (GEOSS) is building a data-driven view of our planet that feeds into models and scenarios. EnviroGRIDS aims at building the capacity of scientist to assemble such a system in the Black Sea Catchment, the capacity of decision-makers to use it, and the capacity of the general public to understand the important environmental, social and economic issues at stake. To achieve its objectives, EnviroGRIDS will build an ultra-modern Grid enabled Spatial Data Infrastructure (GSDI) that will become one component in the Global Earth Observation System of Systems (GEOSS), compatible with the new EU directive on Infrastructure for Spatial Information in the European Union (INSPIRE). EnviroGRIDS will particularly target the needs of the Black Sea Commission (BSC) and the International Commission for the Protection of the Danube River (ICPDR) in order to help bridging the gap between science and policy.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2008-1.1.1 | Award Amount: 4.00M | Year: 2009

The recently finished FP6 RI Black Sea SCENE project has established a Black Sea Scientific Network of leading environmental and socio-economic research institutes, universities and NGOs from the countries around the Black Sea and has developed a distributed virtual data and information infrastructure that is populated and maintained by these organisations to improve the identification, access, exchange, quality indication and use of their data and information about the Black Sea. The Black Sea SCENE research infrastructure stimulates scientific cooperation, exchange of knowledge and expertise, and strengthens the regional capacity and performance of marine environmental data and information management, underpins harmonization with European marine data quality control/assessment procedures and adoption of international meta-data standards and data-management practices, providing improved data & information delivery services for the Black Sea region at a European level. The Up-Grade of Black Sea SCENE project aims: a) to extend the existing research infrastructure with 19 marine environmental institutes/organizations from the 6 Black Sea countries, b) to implement the results of the Joint Research Activities of the FP6 RI SeaDataNet project (common communication standards and adapted technologies to ensure the datacenters interoperability), c) to network the existing and new Black Sea datacenters, active in data collection, and provide integrated databases of standardized quality on-line, d) to realize and improve on-line access to in-situ and remote sensing data, meta-data and products and e) to adopt standardized methodologies for data quality checking to ensure the quality, compatibility and coherence of the data issuing from so many sources. The Up-Grade Black Sea SCENE project is undertaken by 51 partners of which 43 are located in the Black Sea countries.


Alexeyev C.N.,Taurida National University
Journal of Optics (United Kingdom) | Year: 2012

We study the question of robustness of optical vortices (OVs) in twisted anisotropic and elliptical fibres with respect to external perturbations which do not depend on the longitudinal coordinate. On the basis of the developed modification of the coupled mode theory we show that the topological charge carried by OVs in twisted elliptical and anisotropic fibres proves to be robust with respect to induced material anisotropy of the fibre. In contrast, OVs and the topological charge carried are unstable with respect to induced z-independent additional ellipticity of the transverse cross-section of the fibre. In this case OVs are found to invert their initial topological charge upon propagation. We also compare the robustness of OVs in twisted fibres with their robustness in ideal fibres. © 2012 IOP Publishing Ltd.


Fadeyeva T.A.,Taurida National University | Volyar A.V.,Taurida National University
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2010

The dynamics of the spin-orbit coupling in elegant and standard Hermite-Gaussian (HG), Laguerre-Gaussian (LG), and Bessel-Gaussian (BG) beams propagating through a uniaxial crystal are analyzed. We consider the structure of the electric fields of the paraxial beams and show that the extreme values of the spin and orbital angular momenta are inherent in the elegant HG and LG of high orders. The spin-orbit coupling in the BG beam of the lowest order can result in nearly 100% energy transport from a vortex-free beam to the vortexbearing beam at a relatively small crystal length. The extreme spin-orbit coupling does not manifest itself in standard HG and LG beams. © 2010 Optical Society of America.


Alexeyev C.N.,Taurida National University
Applied Optics | Year: 2012

We have theoretically studied long-period spun l-helicoidal fibers and their ability to generate singular beams from regular ones. On the basis of perturbation theory in the presence of degeneracy, applied to the scalar waveguide equation, we obtained the structure of coupled modes of such fibers and their spectra. It is shown that the coupled modes consist of the fields, which taken separately bear topological charges that differby l units. We have numerically studied the process of the passage of a Gaussian beam through such a fiber and demonstrated that long-period l-helicoidal fibers have the ability to change - in a certain wavelength range - the topological charge of the incoming Gaussian beam by l units, generating in this way charge-l optical vortex. © 2012 Optical Society of America.


Dzedolik I.V.,Taurida National University | Karakchieva O.,Taurida National University
Applied Optics | Year: 2013

We obtain theoretically the phonon-polariton spectrum in nonlinear dielectric medium with the thirdorder Kerr-type nonlinearity. We investigate the dependence of number of the polariton spectrum branches on the intensity of electromagnetic field and demonstrate that the appearance of new branches located in the polariton spectrum gap is caused by the influence of dispersion of the third-order dielectric susceptibility at the intensive electromagnetic field in the medium. The modulation instability of new spectrum branch waves leads to the appearance of the cnoidal waves or solitons. These new nonlinear waves one can use for designing optical devices such as the nonlinear optical filter converter. © 2013 Optical Society of America.


Volyar Alexander V.,Taurida National University
Ukrainian Journal of Physical Optics | Year: 2013

We have considered a new type of singular beams called as optical quarks. They have fractional topological charges being equal to half an integer and they possess rather unique properties. There are four types of optical quarks, even and odd ones, which reveal the opposite signs of topological charges. The sums or differences of the even and odd quarks form standard vortex or non-vortex beams with the topological charges of integer order. All the quarks in the same beam annihilate and the beam vanishes. The analysis of angular spectra of the optical quarks shows that the latter represent structurally unstable forms of field under condition of free-space propagation. We have analysed their propagation properties for different types of beam envelope, including a symmetric beam array with discrete optical quarks. We have discussed the properties of possible structurally stable forms of the quarks and the media capable of maintaining the optical quarks.


Alexeyev C.N.,Taurida National University
Applied Optics | Year: 2013

We have studied theoretically reflecting and transmitting properties of Bragg multihelicoidal spun fibers, in which refractive index distribution features l helical branches and possesses an l-fold symmetry in the transverse cross section. It is shown that for a special choice of the profile function modulation, such fibers in certain spectral ranges have the property to change the topological charge of the incoming Gaussian beam in the reflected field by l units. This property could be used for narrowband generation of optical vortices (OVs) from Gaussian beams and for changing the topological charge of incoming OVs. © 2013 Optical Society of America.


Alexeyev C.N.,Taurida National University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

In this paper, we have studied the propagation of light in a p array, that is, a circular array of strongly anisotropic fibers, orientation of whose anisotropy axes linearly depends on the angular position of the fiber in the array and makes an integer number of full rotations p while tracing along its contour. We have obtained the spectrum and the structure of supermodes for such a system and have shown that they consist of two discrete optical vortices nestled in the opposite circular polarizations. We have found the expressions for topological charges of such vortices. We have also studied the angular momentum carried by these supermodes. We have obtained the expression for the evolution of an arbitrary excitation created at the array's input upon its discrete diffraction in the array. As an example, we have examined the propagation of the set of circularly polarized fundamental modes excited at the input end with equal weights and phases. We have demonstrated that, in certain cross sections, the p array generates a discrete circularly polarized optical vortex, whose topological charge is determined by the array's index p. In this way, we have shown that the p arrays enable polarization control over phase singularities being a discrete analog of the q plates. © 2012 American Physical Society.


Dzedolik I.V.,Taurida National University | Karakchieva O.,Taurida National University
Journal of the Optical Society of America B: Optical Physics | Year: 2013

We theoretically investigate the properties of vector and scalar phonon-polariton cnoidal waves and spatial solitons propagating in a boundless dielectric medium. We obtain analytically the expressions for the envelopes of linearly and circularly polarized nonlinear polariton waves in self-focusing and self-defocusing media. The expressions of spatial solitons and cnoidal waves describe one and several flat flows of polaritons for the linearly polarized wave, respectively. The equation for a right or left circularly polarized polariton scalar wave has a soliton solution and a cnoidal wave solution. The polariton vector wave with right and left polariton spiralities has an analytical solution too. Also we examine the linearly and circularly polarized polariton wave instability in the nonlinear dielectric medium. © 2013 Optical Society of America.

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