Abstract The indiscriminate use of allopathic drugs has selected resistant bacterial and fungal populations which represents a severe public health problem worldwide. On the other hand, plants are in a prominent position due to the capability to synthesize structurally complex bioactive metabolites that can be an alternative to resistant microorganisms’ control. In this work, we evaluated the chemical composition and the antimicrobial, antioxidant, and cytotoxic potential of the fractionated extract of C. savannarum in ethyl acetate. The extract of C. savannarum was divided into 12 fractions that were submitted to phytochemical screening, minimum inhibitory concentration (MIC), reduction of 1,1-diphenyl-2-picrylhydrazine (DPPH), and hemolytic activity of sheep erythrocytes assays. During the investigation, all extract fractions presented alkaloids, triterpenoids, steroids, and phenolic compounds in qualitative analyses, while in the quantitative evaluation, we observed the presence of both phenols and flavonoids in these fractions. Among the fraction, the highest phenolic content was observed in the Cs23-24 fraction (2.480 mg EAG/g), while the Cs31-34 fractions presented the highest amount of flavonoid (182.25 μg EQ/100 mg). Nine of the 12 fractions of the moss species’ extract showed antimicrobial action Against Gram-positive bacteria: Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis; Gram-negative bacteria: Pseudomonas aeruginosa; and also antifungal activity against Candida albicans and Candida glabata. The cytotoxic assay demonstrated that the tested fractions did not induce hemolysis at concentrations 10 and 100(µG/ML). In the antioxidant evaluation, the Cs55-69 fractions were the ones that presented the highest scavenging activity (57, 0%) followed by the Cs45-54 fraction (42.7%). Overall, the evaluation of the biological potential of the fractionated extracts of Campylopus savannarum showed promising data, in the search for natural antimicrobial compounds.

Resumo O uso indiscriminado de drogas alopáticas tem selecionado populações bacterianas e fúngicas resistentes, o que representa um grave problema de saúde pública mundial. Por outro lado, as plantas ocupam posição de destaque devido à capacidade de sintetizar metabólitos bioativos estruturalmente complexos que podem ser uma alternativa ao controle de microrganismos resistentes. Neste trabalho, avaliamos a composição química e o potencial antimicrobiano, antioxidante e citotóxico do extrato fracionado de C. savannarum em acetato de etila. O extrato de C. savannarum foi dividido em 12 frações que foram submetidas aos ensaios de triagem fitoquímica, concentração inibitória mínima (CIM), redução de 1,1-difenil-2-picrilhidrazina (DPPH) e atividade hemolítica de eritrócitos de ovinos. Durante a investigação, todas as frações do extrato apresentaram alcalóides, triterpenóides, esteróides e compostos fenólicos nas análises qualitativas, enquanto na avaliação quantitativa, observou-se a presença de fenóis e flavonoides nessas frações. Dentre as frações, o maior teor de fenólicos foi observado na fração Cs23-24 (2,480 mg EAG/g), enquanto as frações Cs31-34 apresentaram a maior quantidade de flavonoides (182,25 μg EQ/100 mg). Nove das 12 frações do extrato da espécie de musgo apresentaram ação antimicrobiana contra bactérias Gram-positivas: Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis; Bactérias Gram-negativas: Pseudomonas aeruginosa; e também atividade antifúngica contra Candida albicans e Candida glabata. O ensaio citotóxico demonstrou que as frações testadas não induziram hemólise nas concentrações 10 e 100(µG/ML). Na avaliação antioxidante, as frações Cs55-69 foram as que apresentaram maior atividade seqüestradora (57,0%) seguida da fração Cs45-54 (42,7%). No geral, a avaliação do potencial biológico dos extratos fracionados de Campylopus savannarum mostrou dados promissores, na busca de compostos antimicrobianos naturais.

Abstract Coal and biomass are energy sources with great potential for use in Brazil. Coal-biomass co-gasification enables the combination of the positive characteristics of each fuel, besides leading to a cleaner use of coal. The present study evaluates the potential of co-gasification of binary coal-biomass blends using sources widely available in Brazil. This analysis employs computational simulations using a reliable thermodynamic equilibrium model. Favorable operational conditions at high temperatures are determined in order to obtain gaseous products suitable for energy cogeneration and chemical synthesis. This study shows that blends with biomass ratios of 5% and equivalence ratios ≤ 0.3 lead to high cold gas efficiencies. Suitable gaseous products for chemical synthesis were identified at biomass ratios ≤ 35% and moisture contents ≥ 40%. Formation of undesirable nitrogen and sulfur compounds was also analyzed.

Computational Fluid Dynamics (CFD) is widely used by polymer processing industries in order to evaluate polymeric fluid flows. A successful computational code must provide reliable predictions (modeling) in a fast and efficient way (simulation). In this work, a new approach to solve the governing equations of viscoelastic fluid flows is proposed. It is based on the finite-volume method with collocated arrangement of the variables, using high-order approximations for the linear and nonlinear average fluxes in the interfaces and for the nonlinear terms obtained from the discretization of the constitutive equations. The approximations are coupled to the Weighted Essentially Non-Oscillatory (WENO) scheme to avoid oscillations in the solution. The Oldroyd-B model is used to describe the rheological behavior of the viscoelastic fluid. The average values of the variables in the volumes are used during the resolution, and the point values are recovered in the post-processing step by deconvolution of the average values. The nonlinear system, resulting from the discretization of the equations, is solved simultaneously using a Newton-like method. The obtained solutions are oscillation-free and accurate, demonstrated by the application on a classic problem in computational fluid dynamics, the slip-stick flow.