Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of activated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fibers were physically prepared from the carbonization of the Kevlar and its later activation with CO2 and steam of water, by the other hand; the chemically activated fibers were obtained by means of the impregnation of the material with phosphoric acid and their later carbonization. Different conditions were used and preliminary analyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterized by N2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off were also evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strong conditions respect to the commonly used such as water steam, high phosphoric acid concentrations and methods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.

Os Rotifera constituem o grupo dominante de zooplâncton da maioria das represas, representando mais de 60% do total da comunidade zooplanctônica. Por serem organismos oportunistas, adaptam-se com facilidade às mudanças das condições ambientais e, assim, dificilmente se encontra um padrão constante de composição e ocorrência de espécies no espaço e no tempo. Com o objetivo de verificar como as mudanças na composição e na dominância das espécies ocorrem em um sistema dinâmico, no caso Represa do Broa, em curtos intervalos de tempo, foi feito o estudo da variação diária da densidade total de Rotifera e das populações dominantes, no período de 20 dias. Filinia pejleri e Keratella americana foram as espécies dominantes, perfazendo 64,3% do total de Rotifera. Entretanto, em termos diários foi verificado que, nos primeiros cinco dias de estudo, houve a dominância da associação dos gêneros Conochilus (C. coenobasis e C. unicornis) e Keratella (K. americana e K. cochlearis), sendo que no 7º dia o gênero Conochilus foi substituído pelo gênero Filinia, que em associação com o gênero Keratella predominou até o final do período de estudo. Essa mudança na dominância se encontra associada também ao aumento da densidade dos organismos, que por sua vez coincide com o aumento da velocidade do vento ocorrido no dia anterior a esses eventos. O vento pode provocar mudança no comportamento e no metabolismo dos organismos por meio da turbulência, aumentando a taxa reprodutiva que, por sua vez, pode estar associada à maior disponibilidade de alimento através da ressuspensão do material do fundo.

Rotifers are the predominant group of zooplankton found in the majority of reservoirs, constituting more than 60% of the total zooplankton present. Being opportunistic organisms, they easily adapt to changes in environmental conditions, and it is therefore difficult to establish a constant level of composition and occurrence of a species in specific areas at specific times. In order to establish how changes in composition and predominance of a species occurs within a dynamic system, the daily variation in the total density of rotifers and that of the dominant species were studied at short intervals during a period of 20 days at Lobo (Broa) reservoir. Filinia pejleri and Keratella americana were the predominant species, making up 64.3% of the total rotifers. However, during the first five days of the study, there was a predominance of two genera, Conochilus (C. coenobasis and C. unicornis) and Keratella (K. americana and K. cochlearis), with the genus Conochilus being substituted by the genus Filinia from the seventh day onwards, which, together with the genus Keratella, was predominant until the end of the study period. The increase in density of Filinia pejleri and Keratella americana was found to be associated with increased wind speed. The resulting turbulence could cause changes in the behavior and metabolism of the organisms, increasing the rate of reproduction, which in turn could be attributed to the greater availability of food through the suspension of material from the lake bed.