FLORA LIQUÉNICA EPIFÍTICA DE CÁDIZ. l. LOS ALCORNOCALES DE LAS SIERRAS DE ALGECIRAS

This first contribution to the lichen epiphytic flora of the province of Cádiz includes ecological data and comments on literature records from this and nearby territories (portuguese Algarve and the spanish province of Huelva). The species distribution approximation is drawn based on bioclimate of several stations. The catalogue includes records of interest, either because they are new for the spanish lichen flora or because of their chorological relevance. among them: Buellia jorgei G. Samp., Caloplaca pollini (Massal.) Jatta, Fuscidea cyathoides (Ach.) V. Wirth & Vezda, Lecanactis patellarioides (Nyl.) Vainio, Lecanora balearicaRealizamos una primera aportaci6n al conocimiento de la flora epifítica de la provincia de Cádiz. Se incluyen datos ecológicos y se comentan las citas bibliográficas de éste y otros territorios próximos (Algarve portugués y provincia española de Huelva). Presentamos una aproximación a la distribución de las especies en función de las variables bioclimáticas de las distintas estaciones. Entre los táxones del catálogo se incluyen algunos interesantes por ser novedad para la flora española o por su significación corológica, entre ellos destacamos: Buellia jorgei G. Samp., Caloplaca pollinii (Massal.) Jatta, Fuscidea cyathoides (Ach.) V. Wirth & Vézda, Lecanactis patellarioides (Nyl.) Vainio, Lecanora balearica Crespo & Llimona, Maronea constans (Nyl.) Hepp., Parmotrema austrosinense (Zahlbr.) Hale, Parmotrema hypoleucinum (Steiner) Hale, Parmotrema stupeum (Taylor) Hale, Pertusaria caesioalba (Flotow) Nyl., Pertusaria dalmatita Erichsen, Pertusaria ficorum Zahlbr., Pertusaria lecanorodes Erichsen, Pertusaria maximiliana Klem., Pyrrhospora quernea (Dickson) Koerber, Rinodina pruinella Bagl. y Sorothelia confluens Koerber. De todos los táxones catalogados se menciona los pliegos MAF lich testigo

Risk Management at the Institute of Chemistry of the State University of Rio De Janeiro

The present work aims to evaluate the perception of students in relation to the risk of activities carried out in the laboratories (academic and research) of the Institute of Chemistry of the State University of Rio de Janeiro. In laboratories, equipment operating under pressure and hazardous chemical compounds can harm human health or result in accidents, some fatal. Risk assessments were carried out in the laboratories, using nationally accepted risk management standards, to identify the risks that the laboratories are exposed to in relation to fire and explosion safety, as well as to understand the history, causes and consequences of previous accidents. In a simplified way, it was concluded that the perception of risk by students and employees of the Institute of Chemistry is low. Thus, the need for improvements in laboratories was pointed out, to mitigate or eliminate existing risks, in addition to help foster a strong safety culture, through which laboratory risks can be identified and properly managed by all working in such environments. Consequently, the frequency and severity of laboratory accidents is expected to be reduced or even eliminated

Confinement and soliton solutions in the SL(3) Toda model coupled to matter fields

We consider an integrable conformally invariant two dimensional model associated to the affine Kac-Moody algebra SL(3). It possesses four scalar fields and six Dirac spinors. The theory does not possesses a local Lagrangian since the spinor equations of motion present interaction terms which are bilinear in the spinors. There exists a submodel presenting an equivalence between a U(1) vector current and a topological current, which leads to a confinement of the spinors inside the solitons. We calculate the one-soliton and two-soliton solutions using a procedure which is a hybrid of the dressing and Hirota methods. The soliton masses and time delays due to the soliton interactions are also calculated. We give a computer program to calculate the soliton solutions.Comment: plain LaTeX, 37 page

Affine Toda model coupled to matter and the string tension in QCD2_{2}

The $sl(2)$ affine Toda model coupled to matter (ATM) is shown to describe various features, such as the spectrum and string tension, of the low-energy effective Lagrangian of QCD$_{2}$ (one flavor and $N$ colors). The corresponding string tension is computed when the dynamical quarks are in the {\sl fundamental} representation of SU(N) and in the {\sl adjoint} representation of SU(2).Comment: LaTex, 10 pages. Revised version to appear in Phys. Rev.

Multiscale magnetic underdense regions on the solar surface: Granular and Mesogranular scales

The Sun is a non-equilibrium dissipative system subjected to an energy flow which originates in its core. Convective overshooting motions create temperature and velocity structures which show a temporal and spatial evolution. As a result, photospheric structures are generally considered to be the direct manifestation of convective plasma motions. The plasma flows on the photosphere govern the motion of single magnetic elements. These elements are arranged in typical patterns which are observed as a variety of multiscale magnetic patterns. High resolution magnetograms of quiet solar surface revealed the presence of magnetic underdense regions in the solar photosphere, commonly called voids, which may be considered a signature of the underlying convective structure. The analysis of such patterns paves the way for the investigation of all turbulent convective scales from granular to global. In order to address the question of magnetic structures driven by turbulent convection at granular and mesogranular scales we used a "voids" detection method. The computed voids distribution shows an exponential behavior at scales between 2 and 10 Mm and the absence of features at 5-10 Mm mesogranular scales. The absence of preferred scales of organization in the 2-10 Mm range supports the multiscale nature of flows on the solar surface and the absence of a mesogranular convective scale

Comparison of Recent SnIa datasets

We rank the six latest Type Ia supernova (SnIa) datasets (Constitution (C), Union (U), ESSENCE (Davis) (E), Gold06 (G), SNLS 1yr (S) and SDSS-II (D)) in the context of the Chevalier-Polarski-Linder (CPL) parametrization $w(a)=w_0+w_1 (1-a)$, according to their Figure of Merit (FoM), their consistency with the cosmological constant ($\Lambda$CDM), their consistency with standard rulers (Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO)) and their mutual consistency. We find a significant improvement of the FoM (defined as the inverse area of the 95.4% parameter contour) with the number of SnIa of these datasets ((C) highest FoM, (U), (G), (D), (E), (S) lowest FoM). Standard rulers (CMB+BAO) have a better FoM by about a factor of 3, compared to the highest FoM SnIa dataset (C). We also find that the ranking sequence based on consistency with $\Lambda$CDM is identical with the corresponding ranking based on consistency with standard rulers ((S) most consistent, (D), (C), (E), (U), (G) least consistent). The ranking sequence of the datasets however changes when we consider the consistency with an expansion history corresponding to evolving dark energy $(w_0,w_1)=(-1.4,2)$ crossing the phantom divide line $w=-1$ (it is practically reversed to (G), (U), (E), (S), (D), (C)). The SALT2 and MLCS2k2 fitters are also compared and some peculiar features of the SDSS-II dataset when standardized with the MLCS2k2 fitter are pointed out. Finally, we construct a statistic to estimate the internal consistency of a collection of SnIa datasets. We find that even though there is good consistency among most samples taken from the above datasets, this consistency decreases significantly when the Gold06 (G) dataset is included in the sample.Comment: 13 pages, 9 figures. Included recently released SDSS-II dataset. Improved presentation. Main results unchanged. The mathematica files and datasets used for the production of the figures may be downloaded from http://leandros.physics.uoi.gr/datacomp

Higher Grading Conformal Affine Toda Teory and (Generalized) Sine-Gordon/Massive Thirring Duality

Some properties of the higher grading integrable generalizations of the conformal affine Toda systems are studied. The fields associated to the non-zero grade generators are Dirac spinors. The effective action is written in terms of the Wess-Zumino-Novikov-Witten (WZNW) action associated to an affine Lie algebra, and an off-critical theory is obtained as the result of the spontaneous breakdown of the conformal symmetry. Moreover, the off-critical theory presents a remarkable equivalence between the Noether and topological currents of the model. Related to the off-critical model we define a real and local Lagrangian provided some reality conditions are imposed on the fields of the model. This real action model is expected to describe the soliton sector of the original model, and turns out to be the master action from which we uncover the weak-strong phases described by (generalized) massive Thirring and sine-Gordon type models, respectively. The case of any (untwisted) affine Lie algebra furnished with the principal gradation is studied in some detail. The example of $\hat{sl}(n) (n=2,3)$ is presented explicitly.Comment: 28 pages, JHEP styl

A parametrization of the growth index of matter perturbations in various Dark Energy models and observational prospects using a Euclid-like survey

We provide exact solutions to the cosmological matter perturbation equation in a homogeneous FLRW universe with a vacuum energy that can be parametrized by a constant equation of state parameter $w$ and a very accurate approximation for the Ansatz $w(a)=w_0+w_a(1-a)$. We compute the growth index \gamma=\log f(a)/\log\Om_m(a), and its redshift dependence, using the exact and approximate solutions in terms of Legendre polynomials and show that it can be parametrized as $\gamma(a)=\gamma_0+\gamma_a(1-a)$ in most cases. We then compare four different types of dark energy (DE) models: $w\Lambda$CDM, DGP, $f(R)$ and a LTB-large-void model, which have very different behaviors at z\gsim1. This allows us to study the possibility to differentiate between different DE alternatives using wide and deep surveys like Euclid, which will measure both photometric and spectroscopic redshifts for several hundreds of millions of galaxies up to redshift $z\simeq 2$. We do a Fisher matrix analysis for the prospects of differentiating among the different DE models in terms of the growth index, taken as a given function of redshift or with a principal component analysis, with a value for each redshift bin for a Euclid-like survey. We use as observables the complete and marginalized power spectrum of galaxies $P(k)$ and the Weak Lensing (WL) power spectrum. We find that, using $P(k)$, one can reach (2%, 5%) errors in $(w_0, w_a)$, and (4%, 12%) errors in $(\gamma_0, \gamma_a)$, while using WL we get errors at least twice as large. These estimates allow us to differentiate easily between DGP, $f(R)$ models and $\Lambda$CDM, while it would be more difficult to distinguish the latter from a variable equation of state parameter or LTB models using only the growth index.}Comment: 29 pages, 7 figures, 6 table

A new approach to cosmological perturbations in f(R) models

We propose an analytic procedure that allows to determine quantitatively the deviation in the behavior of cosmological perturbations between a given f(R) modified gravity model and a LCDM reference model. Our method allows to study structure formation in these models from the largest scales, of the order of the Hubble horizon, down to scales deeply inside the Hubble radius, without employing the so-called "quasi-static" approximation. Although we restrict our analysis here to linear perturbations, our technique is completely general and can be extended to any perturbative order.Comment: 21 pages, 2 figures; Revised version according to reviewer's suggestions; Typos corrected; Added Reference