Liquid Polymorphism and Density Anomaly in a Lattice Gas Model

We present a simple model for an associating liquid in which polymorphism and density anomaly are connected. Our model combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom represented through thermal \char`\"{}ice variables\char`\"{} . The competition between the directional attractive forces and the soft core potential leads to a phase diagram in which two liquid phases and a density anomaly are present. The coexistence line between the low density liquid and the high density liquid has a positive slope contradicting the surmise that the presence of a density anomaly implies that the high density liquid is more entropic than the low density liquid

LANDSAT and radar mapping of intrusive rocks in SE-Brazil

The feasibility of intrusive rock mapping was investigated and criteria for regional geological mapping established at the scale of 1:500,00 in polycyclic and polymetamorphic areas using the logic method of photointerpretation of LANDSAT imagery and radar from the RADAMBRASIL project. The spectral behavior of intrusive rocks, was evaluated using the interactive multispectral image analysis system (Image-100). The region of Campos (city) in northern Rio de Janeiro State was selected as the study area and digital imagery processing and pattern recognition techniques were applied. Various maps at the 2:250,000 scale were obtained to evaluate the results of automatic data processing

Sunyaev - Zel'dovich fluctuations from spatial correlations between clusters of galaxies

We present angular power spectra of the cosmic microwave background radiation anisotropy due to fluctuations of the Sunyaev-Zel'dovich (SZ) effect through clusters of galaxies. A contribution from the correlation among clusters is especially focused on, which has been neglected in the previous analyses. Employing the evolving linear bias factor based on the Press-Schechter formalism, we find that the clustering contribution amounts to 20-30% of the Poissonian one at degree angular scales. If we exclude clusters in the local universe, it even exceeds the Poissonian noise, and makes dominant contribution to the angular power spectrum. As a concrete example, we demonstrate the subtraction of the ROSAT X-ray flux-limited cluster samples. It indicates that we should include the clustering effect in the analysis of the SZ fluctuations. We further find that the degree scale spectra essentially depend upon the normalization of the density fluctuations, i.e., \sigma_8, and the gas mass fraction of the cluster, rather than the density parameter of the universe and details of cluster evolution models. Our results show that the SZ fluctuations at the degree scale will provide a possible measure of \sigma_8, while the arc-minute spectra a probe of the cluster evolution. In addition, the clustering spectrum will give us valuable information on the bias at high redshift, if we can detect it by removing X-ray luminous clusters.Comment: 11 pages, 4 figures, submitted to Astrophysical Journa

Definição de níveis categóricos de descritores qualitativos, para utilização na caracterização foliar do cupuaçuzeiro.

O conhecimento da variabilidade dentro das populações naturais e nas coleções de cupuaçuzeiro mantidas ex situ é vital para seu aproveitamento aplicado, seja na definição de áreas prioritárias para reservas, como também para conhecer a representatividade desses acessos nas coleções existentes. Características morfológicas das plantas, especialmente relacionadas com a folha, flor e fruto são as mais empregadas para esse fim, pela facilidade de manejo e pelas respostas que proporcionam. Entretanto, há necessidade de definir as ferramentas que farão a aferição dessa variabilidade. Para dar início à definição de descritores qualitativos eficientes, esta pesquisa utilizou os dados de quatro bancos de dados referentes a quatro coleções que compõem o Banco Ativo de Germoplasma (BAG) de cupuaçuzeiro da Embrapa Amazônia Oriental. Foram empregadas 13 variáveis quantitativas de características foliares do cupuaçuzeiro. Verificada a normalidade, os dados foram distribuídos em três quadrantes, os quais foram calculados com base na média e desvio padrão. Cada quadrante recebeu a denominação dos níveis categóricos qualitativos do descritor. Esses descritores passarão a ser utilizados nas caracterizações foliares das novas coleções, e no registro e lançamento de novas cultivares de cupuaçuzeiro

Quantification of Phenolic Constituents and Antioxidant Activity of Pterodon emarginatus Vogel Seeds

In the present study the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents and the antioxidant activity of Pterodon emarginatus seeds were investigated in several samples prepared with different extraction procedures: essential oil (EO) using a Clevenger-type apparatus; hexanic (HF), ethyl acetate (EAF), buthanolic (BF) and methanolic (MF) fractions using Soxhlet extraction, and extracts (1 g/extract) obtained from different methods: reflux 80°C/30 min, ultrasound/30 min, static maceration/48 h and heating plate 100°C/45 min. These extracts were prepared using water or ethanol/water at 30:70 v/v, 50:50 v/v or 70:30 v/v. Antioxidant activity [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH)] was tested only in the fractions obtained from Soxhlet extraction. The extract obtained from reflux using ethanol/water (70:30, v/v) showed the highest phenolic constituents level. The EAF, BF and MF showed DPPH scavenging activities with IC50=163.22, 18.89 and 10.15 μg/ml, respectively

On the Number Density of Sunyaev-Zel'dovich Clusters of Galaxies

If the mean properties of clusters of galaxies are well described by the entropy-driven model, the distortion induced by the cluster population on the blackbody spectrum of the Cosmic Microwave Background radiation is proportional to the total amount of intracluster gas while temperature anisotropies are dominated by the contribution of clusters of about 10^{14} solar masses. This result depends marginally on cluster parameters and it can be used to estimate the number density of clusters with enough hot gas to produce a detectable Sunyaev-Zel'dovich effect. Comparing different cosmological models, the relation depends mainly on the density parameter Omega_m. If the number density of clusters could be estimated by a different method, then this dependence could be used to constrain Omega_m.Comment: 8 pages, 3 figures, submitted to ApJ Letter

Caracterização de frutos de acessos de cupuaçuzeiro, procedentes de plantios comerciais de Tomé Açu - PA (clones elites I).

A variabilidade existente nos plantios de cupuaçuzeiro do município de Tomé Açu, especialmente para número e conformação dos frutos, merece ser preservada e caracterizada para utilização nos futuros programas de melhoramento do cupuaçuzeiro. Esta pesquisa teve por objetivo efetuar a caracterização de fruto dos acessos dessa coleção. Foram estudados 50 clones, em ensaio instalado em T. Açu, no delineamento de blocos inteiramente casualizados com 10 repetições, com uma planta por parcela. Em cada planta foram analisados cinco frutos por safra, provenientes de coletas realizadas no período de 1999 a 2011. Os resultados apontaram boa variabilidade entre os tratamentos para quase todas variáveis analisadas. Foi elaborado o perfil de cada clone para os descritores empregados. As características morfológicas dos frutos, associadas à produção de frutos nas diferentes safras, e resistência à vassoura de bruxa, permitirão identificar clones promissores para utilização no programa de melhoramento genético

Monitoring the quality of sliced pork ham packed in different modified atmospheres during 45 days of storage

This study, financed by EXTRASLICED45 project, promoted by Primor Charcutaria-Prima S.A. and focused on extra-sliced pork ham, aims to use different modified atmosphere packaging (MAP) as a preservation technique for extending the lifetime of the product