Why is d-wave pairing in HTS robust in the presence of impurities?

In the recent theory of strong correlations by Kulic and Zeyher it has been shown that by lowering doping concentration a forward peak in the charge scattering channel is developed. Accordingly, near the optimal doping the nonmagnetic scattering is pronounced in the d-channel and its effect on d-wave pairing is reduced. As a consequence, d-wave pairing is robust against defects and impurities, the order parameter keeps its d-wave shape for any scattering rate and the density of states becomes finite at the Fermi surface. For large doping scattering anisotropy parameter is small and d-wave loses its robustness. The theory is generally formulated for the bi-layer model by including: 1) intra- and inter-plane pairing; 2) intra- and inter-plane impurities.Comment: Complete revision, 4 pages with 2 PS figures, RevTeX, submitted to Phys. Rev. Let

Analysis of benzoic and cinnamic acid derivatives of some medicinal plants in Serbia

Natural phenolics, which are ubiquitously distributed in plants, have been reported as functional factors in phytotherapy. We have examined phenolic compounds in the leaves and inflorescences of five significant medicinal plants of different plant families: Salvia officinalis (Lamiaceae); Achillea clypeolata (Asteraceae); Nymphaea alba (Nymphaeaceae); Rumex acetosella (Polygonaceae) and Allium ursinum (Alliaceae). The examined species were rich in total phenolics (up to 30.88 mg/g dry weight). According to their total phenolics contents, the plants can be arranged in the following order: A. clypeolata>N. alba>S. officinalis>R. acetosella>A. ursinum. Free phenolics prevailed in all species in comparison to the bound forms (63.72-82.68% of total phenolics). The highest content of total free phenolics was measured in the tissues of A. clypeolata and N. alba, and the lowest in A. ursinum. Five phenolic acids were isolated and measured. p-Coumaric and ferulic acids as derivatives of cinnamic acid prevailed in the leaves of R. acetosella and A. ursinum (up to 4.81%).Projekat ministarstva br. 17301

Distribution of macrolide-resistant genes among isolates of macrolideresistant Streptococcus pyogenes and Streptococcus pneumoniae in Serbia

Macrolide resistance in Streptococcus pneumoniae and in group A streptococci (GAS) is a significant problem worldwide. In Serbia, data on the mechanisms of resistance and the corresponding resistance genes in streptococci are largely lacking. Therefore, we analyzed the distribution of macrolide resistance phenotypes and genotypes in 44 macrolideresistant GAS (MRGAS) and 50 macrolide-resistant S. pneumoniae (MRSP) isolates collected in the same period. The double disk diffusion test and PCR were used to analyze resistance phenotypes and resistance genes, respectively. Among MRSP, the MLSB phenotype dominated, whereas the M phenotype was the most prevalent among MRGAS isolates. Consequently, in MRSP, the ermB gene was the most common (n=40, 80%), followed by the mefA gene (n=7,14%). In MRGAS strains, mefA dominated (n=27,61%), followed by ermA (n=15, 33%) and ermB (n=3, 7%). In 3 MRSP isolates no resistance genes were detected, while one MRGAS strain with iMLSB phenotype harbored both ermA and mefA genes

The potential of four woody species for the revegetation of fly ash deposits from the 'Nikola Tesla-a' thermoelectric plant (Obrenovac, Serbia)

Four woody species, Tamarix tentandra Pallas, Populus alba L. and Robinia pseudoacacia L. (planted) and Amorpha fruticosa L. (naturally colonized) were studied at two fly ash deposit lagoons, weathered 3 (L1) and 11 years (L2). All species were assessed in terms of their invasive ability, photosynthetic efficiency, photosynthetic pigments and damage symptoms, while the characteristics of the habitat were assessed in terms of trace element content and the pH and EC of the ash. A reduced vitality of all populations growing on the ash was observed, except for the naturally colonized A. fruticosa. High vitality on all sites, except at L2, increased chlorophyll content and absence of damage symptoms indicates a tolerance in relation to the uptake of toxic elements from the ash. Therefore, the characteristics of naturally colonized species can be used for modeling future actions of biological restoration of fly ash deposits.Projekat ministarstva br. 17301

A contribution to studies of the ruderal vegetation of Southern Srem, Serbia

Floristic research investigating the presence and phytocoenological differentiation of ruderal vegetation, and how it is conditioned structurally and anthropogenically, was undertaken over a period of several years (2007-10) in the south Srem region. The ruderal flora of the research area comprised 249 plants categorized into 63 families, of which the most frequent were: Asteraceae (36), Poaceae (29), Fabaceae (18), Lamiaceae (15), Polygonaceae (15), Brassicaceae (11) and Rosaceae (11). Three ruderal communities are analyzed in this work: Asclepietum syriacae Kojić et al., 2004, as well as Chenopodio-Ambrosietum artemisiifoliae ass. nova and Amorpho-Typhaetum ass. nova, which are described for the first time. It was established that the level of moisture at the habitat, anthropogenic factors, and the immediate proximity to cultivated areas had the most pronounced effect on the differentiation of the researched vegetation.Projekat ministarstva br. 17301

Anisotropic impurities in anisotropic superconductors

Physical properties of anisotropic superconductors like the critical temperature and others depend sensitively on the electron mean free path. The sensitivity to impurity scattering and the resulting anomalies are considered a characteristic feature of strongly anisotropic pairing. These anomalies are usually analyzed in terms of s-wave impurity scattering which leads to universal pair breaking effects depending on only two scattering parameters, the mean free path and the impurity cross section. We investigate here corrections coming from anisotropies in the scattering cross section, and find not only quantitative but also qualitative deviations from universal s-wave isotropic pairbreaking. The properties we study are the transition temperature, the density of states, quasiparticle bound states at impurities, and pinning of flux lines by impurities.Comment: 19 page

Systems of Hess-Appel'rot Type and Zhukovskii Property

We start with a review of a class of systems with invariant relations, so called {\it systems of Hess--Appel'rot type} that generalizes the classical Hess--Appel'rot rigid body case. The systems of Hess-Appel'rot type carry an interesting combination of both integrable and non-integrable properties. Further, following integrable line, we study partial reductions and systems having what we call the {\it Zhukovskii property}: these are Hamiltonian systems with invariant relations, such that partially reduced systems are completely integrable. We prove that the Zhukovskii property is a quite general characteristic of systems of Hess-Appel'rote type. The partial reduction neglects the most interesting and challenging part of the dynamics of the systems of Hess-Appel'rot type - the non-integrable part, some analysis of which may be seen as a reconstruction problem. We show that an integrable system, the magnetic pendulum on the oriented Grassmannian $Gr^+(4,2)$ has natural interpretation within Zhukovskii property and it is equivalent to a partial reduction of certain system of Hess-Appel'rot type. We perform a classical and an algebro-geometric integration of the system, as an example of an isoholomorphic system. The paper presents a lot of examples of systems of Hess-Appel'rot type, giving an additional argument in favor of further study of this class of systems.Comment: 42 page

Infrared and Raman spectra of LiV2O5 single crystals

The phonon dynamics of LiV2O5 single crystals is studied using infrared and Raman spectroscopy techniques. The infrared-active phonon frequencies and dielectric constants are obtained by oscillator fitting procedure of the reflectivity data measured at room temperature. The Raman scattering spectra are measured at room temperature and at T=10 K in all nonequivalent polarized configurations. The assignment of the phonons is done by comparing the infrared and Raman spectra of LiV2O5 and NaV2O5. The factor-group-analysis of the LiV2O5 crystal symmetry and of its constituent layers is performed to explain the symmetry properties of the observed modes. We concluded that layer symmetry dominates in the vibrational properties of this compound.Comment: 10 pages, 5 figure

Systems of Hess-Appel'rot type

We construct higher-dimensional generalizations of the classical Hess-Appel'rot rigid body system. We give a Lax pair with a spectral parameter leading to an algebro-geometric integration of this new class of systems, which is closely related to the integration of the Lagrange bitop performed by us recently and uses Mumford relation for theta divisors of double unramified coverings. Based on the basic properties satisfied by such a class of systems related to bi-Poisson structure, quasi-homogeneity, and conditions on the Kowalevski exponents, we suggest an axiomatic approach leading to what we call the "class of systems of Hess-Appel'rot type".Comment: 40 pages. Comm. Math. Phys. (to appear

A HIGH RESOLUTION TEMPERATURE CLIMATOLOGY FOR THE GREATER ALPINE REGION (GAR)

The Greater Alpine Region (the GAR) covering the area between 4-19°E and 43-50°N and an altitude range between 0 and more than 4000 m asl. offers a challenging climate worth to be studied in any detail. However, it is surprising that up to now no comprehensive Alpine Temperature Climatology covering the whole region is existing. To overcome this deficiency as a first step we want to produce monthly temperature maps for this region in spatial resolution as high as possible. The period under investigation will be 1961-1990. In this paper we will describe the first steps of our initiative as well as the further plans