Abstract Antibiotics have shown less efficiency against resistance of pathogenic microorganisms. As a result, research centers have sought therapeutic alternatives against multidrug resistance of bacteria to antibiotics, one of which is using plant extracts. Bamboo extracts are used for several medicinal purposes. This study aimed to evaluate the antibacterial potential of hydroalcoholic extracts of culms and leaves of the species Guadua aff. lynnclarkiae on strains of Staphylococcus aureus, Streptococcus pneumoniae, and Klebsiella pneumoniae. We evaluated the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Only the leaves of G. aff. lynnclarkiae showed a bactericidal effect for all tested strains with MBC ranging from 1.55 mg ml-1 to 25 mg ml-1. The culms had bacteriostatic action with MIC ranging from 1.55 mg ml-1 to 6.25 mg ml-1, and bactericidal action at the concentration of 6.25 mg ml-1 only for S. aureus. This study provides bases for the use of this Amazonian native bamboo in bioprospecting.

Resumo Os antibióticos têm mostrado menor eficiência contra a resistência de microrganismos patogênicos. Assim sendo, centros de pesquisa têm buscado alternativas terapêuticas contra a multirresistência das bactérias aos antibióticos, sendo uma delas o uso de extratos vegetais. Extratos de bambu têm sido usados para diversos fins medicinais. Este trabalho teve como objetivo avaliar o potencial antibacteriano de extratos hidroalcoólicos de colmos e folhas da espécie Guadua aff. lynnclarkiae em cepas de Staphylococcus aureus, Streptococcus pneumoniae e Klebsiella pneumoniae. Avaliamos a concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM). Apenas as folhas de G. aff. lynnclarkiae mostraram efeito bactericida para todas as cepas testadas com CBM variando de 1,55 mg ml-1 a 25 mg ml-1. Os colmos apresentaram ação bacteriostática com CIM variando de 1,55 mg ml-1 a 6,25 mg ml-1, e ação bactericida na concentração de 6,25 mg ml-1 apenas para S. aureus. Este estudo fornece bases para o uso deste bambu nativo da Amazônia na bioprospecção.

Em algumas aplicações, a detecção de defeitos não é suficiente para a segurança operacional de componentes e estruturas. Deste modo, as técnicas não destrutivas precisam ser adaptadas para a análise do estado de tensões atuantes no componente. Este trabalho apresenta os esforços despendidos no desenvolvimento de sistemas não destrutivos de análise de tensões, voltados para o monitoramento do estado de tensões atuantes em arames da armadura de tração de Risers flexíveis utilizados para o transporte de petróleo e seus derivados. Combinando técnicas como a Análise Harmônica do Campo Magnético Tangencial, Análise Incremental da Permeabilidade Magnética e Análise Multi-freqüência das Correntes Parasitas os resultados mostraram boa correlação entre os carregamentos aplicados e as medidas micromagnéticas, mostrando a grande aplicabilidade das técnicas magnéticas para a caracterização de materiais de engenharia.

In some applications, the detection of defects is not enough for safety control. In these situations, non-destructive techniques must be adapted for stress analysis. This work presents the development of a micromagnetic stress analysis method, using a combination of the harmonic analysis of the tangential magnetic field, the incremental permeability and multi frequency eddy current methods, to be applied for the stress measurements of flexible riser tensile armours. The results showed high correlations between the micromagnetic results and the applied load stress, even in the presence of a lift off layer. This work illustrates the good potential of micromagnetic techniques for the stress characterization.

A moving bed bioreactor containing cubes of polyether foam immersed in a synthetic wastewater (an aqueous mixture of meat extract, yeast extract, dextrose, meat peptone, ammonium chloride, potassium chloride, sodium chloride, sodium bicarbonate, potassium mono-hydrogen-phosphate and magnesium sulphate) was used to evaluate bacterial growth and biomass yield parameters based on Monod's equation. The wastewater was supplied in the bottom of the equipment flowing ascending in parallel with a diffused air current that provided the mixing of the reactor content. Suspended and attached biomass concentration was measured through gravimetric methods. Good agreement was found between experimental kinetic parameters values and those obtained by other researchers. The only significant difference was the high global biomass content about 2 times the values obtained in conventional processes, providing high performance with volumetric loading rates up to 5.5 kg COD/m³/d.

An experimental study was carried out aiming to evaluate the performance of a three-phase fluidized bed bioreactor (FBBR) used to treat milk wastewater. In this study three different concentrations of milk wastewater substrate (462, 825 and 1473 mg O2/L) were tested. Using the same number of support particles, the results demonstrate that the average efficiency of COD removal decreased as the concentration of organic load in the substrate was increased. The growth of microorganism in the FBBR was followed by a count of viable cells in both liquid phase and the biofilms attached to the support. An increased number of viable cells were observed inside the reactor when it was used to degrade higher organic loads, with most of the cells on the support. The higher concentration of active biomass was responsible for achieving a relatively high absolute degradation of the wastewater containing the high organic load.