Properties of the open cluster Tombaugh 1 from high resolution spectroscopy and uvbyCaHβ\beta photometry

Open clusters can be the key to deepen our knowledge on various issues involving the structure and evolution of the Galactic disk and details of stellar evolution because a cluster's properties are applicable to all its members. However the number of open clusters with detailed analysis from high resolution spectroscopy and/or precision photometry imposes severe limitation on studies of these objects. To expand the number of open clusters with well-defined chemical abundances and fundamental parameters, we investigate the poorly studied, anticenter open cluster Tombaugh 1. Using precision uvbyCaH$\beta$ photometry and high resolution spectroscopy, we derive the cluster's properties and, for the first time, present detailed abundance analysis of 10 potential cluster stars. Using radial position from the cluster center and multiple color indices, we have isolated a sample of unevolved probable, single-star members of Tombaugh 1. The weighted photometric metallicity from $m_1$ and $hk$ is [Fe/H] = -0.10 $\pm$ 0.02, while a match to the Victoria-Regina Str\"{o}mgren isochrones leads to an age of 0.95 $\pm$ 0.10 Gyr and an apparent modulus of $(m-M)$ = 13.10 $\pm$ 0.10. Radial velocities identify 6 giants as probable cluster members and the elemental abundances of Fe, Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Y,Ba, Ce, and Nd have been derived for both the cluster and the field stars. Tombaugh 1 appears to be a typical inner thin disk, intermediate-age open cluster of slightly subsolar metallicity, located just beyond the solar circle, with solar elemental abundance ratios except for the heavy s-process elements, which are a factor of two above solar. Its metallicity is consistent with a steep metallicity gradient in the galactocentric region between 9.5 and 12 kpc. Our study also shows that Cepheid XZ CMa is not a member of Tombaugh 1, and reveals that this Cepheid presents signs of barium enrichment.Comment: 74 pages, 15 figures, 13 tables; Accepted for publication in A

Chemical abundances and kinematics of barium stars

In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of $alpha$-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anti-correlated with the metallicity. Our kinematical analysis showed that 90% of the barium stars belong to the thin disk population. Based on their luminosities, none of the barium stars are luminous enough to be an AGB star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.Comment: 30 pages, 26 figures, 18 tables, accepted for publication in MNRA

Optimization of phenol degradation and its derivatives using photo-Fenton and application industrial

In industrial effluent are common persistent organic pollutants found that even low concentrations have a high potential carcinogenic and/or mutagenic, such as phenol and derivatives thereof, which poses risks to the environment. This work has identified and measured through high-performance liquid chromatography (HPLC) and its phenol formed as intermediate and also the amount of total organic carbon (TOC). Degradation was evaluated using the same process of photo-Fenton treatment (Fe2+/H2O2/UV) applying annular reactor and a kinetic study was carried out in terms of TOC. The experimental design was the type central composite. In the process used a photochemical reactor annular counter optimized in the following conditions: [Fe2+]=14.15 mg L-1, [H2O2]=1663.40 mgL-1 at pH 3 for 126.18 minutes, obtaining a mineralization 99.89% TOC and [Fe2+]=15 mgL-1 [H2O2]=1800 mgL-1 in 120 minutes a percentage of 100% phenol degradation, respectively. The kinetic model adopted (Lumped Kinetic Model) allowed satisfactory way of representing (R2=0.9892). The photo-Fenton process proved to be efficient for degradation of phenol and intermediates can be incorporated as part of the effluent treatment systems, making it an effective alternative to the complete degradation of the pollutants thereby relieving the impact on water resources and reducing contamination by-products end of the process. Keywords: Advanced oxidation processes;  Phenol, Homogeneous processes; Photo-Fenton

Geotecnologia na educação ambiental: a diversidade da vegetação do Pantanal brasileiro.

Este trabalho foi organizado com o objetivo de dar suporte a pesquisas ambientais na região do Pantanal e ser utilizado como material didático. O Pantanal brasileiro está inserido na Bacia do Alto rio Paraguai (BAP) e ocupa uma área de 138.183 km2. Essa região é carente de informações devido a grande dificuldade de realização de trabalhos de campo provocada pela ocorrência de ciclos periódicos de inundação. Desenvolvido em forma de multimídia esse trabalho reúne 575 fotografias organizadas em capítulos segundo as sub-regiões do Pantanal brasileiro. Para a estruturação das informações foi utilizado o software Macromedia Flash Professional 8. Cada capítulo descreve as principais características ambientais de cada sub-região do Pantanal brasileiro tais como delimitação e localização, geologia, geomorfologia, hidrologia, vegetação e sistema produtivo. As informações ambientais foram obtidas dentro do âmbito do Projeto Levantamento e mapeamento dos remanescentes da cobertura vegetal do bioma Pantanal, período de 2002 na escala de 1:250.000 - PROBIO-Pantanal e num banco de dados multitemático do Pantanal, estruturado em SIG/SPRING. Cada sub-região é representada por imagens, em composição colorida, obtidas do satélite Landsat 7 e recortadas. Essas imagens trazem localizados os pontos que são acessos para as fotos aqui apresentadas, cuja localização foi feita em função de coordenadas obtidas em campo por GPS. As fotografias trazem informações sobre os tipos de vegetação: Floresta Estacional Semidecidual (Mata), Floresta Estacional Decidual (Mata Seca), Savana (Cerrado), Savana Estépica (Chaco), Formações Pioneiras, Áreas de Tensão Ecológica ou Contatos Florísticos e Pecuária sobre pastagem plantada. Além disso, a cada fotografia também estão associadas informações sobre o tipo de solo, relevo e grau de inundação, município, Estado, coordenadas geográficas obtidas por GPS no ponto observado e data da aquisição da foto. O esforço para disponibilizar informações sobre os diferentes tipos de vegetação do Pantanal, retratando a diversidade de ambiente resultou no livro digital "Fisionomias da Vegetação nas Sub-regiões do Pantanal Brasileiro"

The Chemodynamical Nature of the Triangulum-Andromeda Overdensity

We present a chemodynamical study of the Triangulum-Andromeda overdensity (TriAnd) employing a sample of 31 candidate stars observed with the GRACES high-resolution ($R$=40,000) spectrograph at the Gemini North (8.1 m) telescope. TriAnd is a stellar substructure found toward the outer disk of the Milky Way, located at $R_{\rm GC}\sim 18$ kpc from the Sun, toward Galactic latitude $b \sim 25${\deg}. Most stars in our sample have dynamical properties compatible with a disk stellar population. In addition, by applying an eccentricity cut, we are able to detect a stellar contamination that seems to be consistent with an accreted population. In chemical abundance space, the majority of our TriAnd candidates are similar to the outer thin-disk population, suggesting that the overdensity has an \textit{in situ} origin. Finally, the found accreted halo interlopers spatially overlapping with TriAnd should explain the historical discussion of the overdensity's nature due to its complex chemical patterns.Comment: Published in The Astrophysical Journal (ApJ

Chemical abundances of the young inner-disk open cluster NGC 6705 observed by APOGEE: sodium-rich and not α\alpha-enhanced

Previous results in the literature have found the young inner-disk open cluster NGC 6705 to be mildly $\alpha$-enhanced. We examined this possibility via an independent chemical abundance analysis for 11 red-giant members of NGC 6705. The analysis is based on near-infrared APOGEE spectra and relies on LTE calculations using spherical model atmospheres and radiative transfer. We find a mean cluster metallicity of $\rm [Fe/H] = +0.13 \pm 0.04$, indicating that NGC 6705 is metal-rich, as may be expected for a young inner-disk cluster. The mean $\alpha$-element abundance relative to iron is $\rm \langle [\alpha/Fe]\rangle =-0.03 \pm 0.05$, which is not at odds with expectations from general Galactic abundance trends. NGC 6705 also provides important probes for studying stellar mixing, given its turn-off mass of M$\sim$3.3 M$_\odot$. Its red giants have low $^{12}$C abundances ([$^{12}$C/Fe]=$-$0.16) and enhanced $^{14}$N abundances ([$^{14}$N/Fe]=+0.51), which are key signatures of the first dredge-up on the red giant branch. An additional signature of dredge-up was found in the Na abundances, which are enhanced by [Na/Fe]=+0.29, with a very small non-LTE correction. The $^{16}$O and Al abundances are found to be near-solar. All of the derived mixing-sensitive abundances are in agreement with stellar models of approximately 3.3 M$_{\odot}$ evolving along the red giant branch and onto the red clump. As found in young open clusters with similar metallicities, NGC 6705 exhibits a mild excess in the s-process element cerium, with $\rm [Ce/Fe] = +0.13\pm0.07$.Comment: 17 pages, 10 figures, 6 table

Planejamento fatorial para extra\ue7\ue3o de enzima fibrinolitica de Mucor subtilissimus UCP1262 mediante sistema de duas fases aquosas (PEG/fosfato)

A factorial design was used to select the best conditions of fibrinolytic protease from Mucor subtilissimus by aqueous two-phase system (PEG/phosphate)

Caracterização pedoambiental como subsídio à criação de unidade de conservação no município de Jordão, estado do Acre.

As unidades de conservação constituem instrumentos importantes e estratégicos para a proteção da biodiversidade. O presente estudo objetivou realizar a caracterização pedoambiental (solos e ambientes) de uma área com 61.690 hectares destinada ao estabelecimento de uma unidade de conservação no município de Jordão, Acre, de modo a subsidiar a sua gestão territorial. Para tanto, procederam-se atividades típicas de levantamento de solos, quais sejam: prospecção, abertura de trincheiras, coleta de amostras e descrição morfológica dos perfis de solo, análises físicas e químicas do solo e classificação taxonômica, conforme o Sistema Brasileiro de Classificação de Solos. Ademais, considerando-se os aspectos inerentes a gênese, morfologia e paisagem, realizou-se a estratificação da área em pedoambientes. Observou-se na área a ocorrência de Cambissolos, Gleissolos, Luvissolos, Plintossolos e Neossolos, caracterizados por eutrofismo, alta capacidade de troca de cátions e atividade da fração argila, pouca profundidade do solum e restrição de drenagem, aspectos que conferem a esses solos propriedades intrínsecas em relação aos demais solos da Amazônia. Os pedoambientes verificados apresentam fragilidades quanto ao uso, sobretudo por consequência da pouca pedogênese e dos aspectos de paisagem, refletidos em atributos morfológicos e físicos limitantes, figurando como fatores essenciais à criação de uma unidade de conservação no município. The Conservation Units constitute important and strategic instruments for the protection of biodiversity. The present study aimed to perform the pedoenvironmental characterization (soils and environments) of an area with 61,690 hectares intended as a Conservation Unit in the city of Jordão (Acre), in order to support its territorial management. To this end, typical soil survey activities were performed, namely: prospecting, opening trenches, collecting samples and morphological description of soil profiles, physical and chemical analyses of the soil and taxonomic classification, according to the Brazilian Classification System of Soils. In addition, considering the aspects inherent to the genesis, morphology and landscape, the stratification of the area was carried out in pedoenvironments. The soils were classified as Cambisoils, Gleysoils, Luvisoils, Plintosoils and Neosoils. These soils presented eutrophic character, high cation exchange capacity, high activity of the clay fraction, shallow depth of the solum and drainage restriction, which are characteristic for other Amazonian soils. The pedoenvironmental stratification highlight usage restrictions of the soils, as they show limitations with regard to morphological and physical attributes that appear as essential factors for the creation of a conservation unit in the city

Thin disc, Thick Disc and Halo in a Simulated Galaxy

Within a cosmological hydrodynamical simulation, we form a disc galaxy with sub- components which can be assigned to a thin stellar disc, thick disk, and a low mass stellar halo via a chemical decomposition. The thin and thick disc populations so selected are distinct in their ages, kinematics, and metallicities. Thin disc stars are young (<6.6 Gyr), possess low velocity dispersion ({\sigma}U,V,W = 41, 31, 25 km/s), high [Fe/H], and low [O/Fe]. The thick disc stars are old (6.6<age<9.8 Gyrs), lag the thin disc by \sim21 km/s, possess higher velocity dispersion ({\sigma}U,V,W = 49, 44, 35 km/s), relatively low [Fe/H] and high [O/Fe]. The halo component comprises less than 4% of stars in the "solar annulus" of the simulation, has low metallicity, a velocity ellipsoid defined by ({\sigma}U,V,W = 62, 46, 45 km/s) and is formed primarily in-situ during an early merger epoch. Gas-rich mergers during this epoch play a major role in fuelling the formation of the old disc stars (the thick disc). This is consistent with studies which show that cold accretion is the main source of a disc galaxy's baryons. Our simulation initially forms a relatively short (scalelength \sim1.7 kpc at z=1) and kinematically hot disc, primarily from gas accreted during the galaxy's merger epoch. Far from being a competing formation scenario, migration is crucial for reconciling the short, hot, discs which form at high redshift in {\Lambda}CDM, with the properties of the thick disc at z=0. The thick disc, as defined by its abundances maintains its relatively short scale-length at z = 0 (2.31 kpc) compared with the total disc scale-length of 2.73 kpc. The inside-out nature of disc growth is imprinted the evolution of abundances such that the metal poor {\alpha}-young population has a larger scale-length (4.07 kpc) than the more chemically evolved metal rich {\alpha}-young population (2.74 kpc).Comment: Submitted to MNRAS. This version after helpful referee comments. Comments welcome to [email protected]