The present work aims to evaluate the manufacturing processes of free-standing graphene oxide (GO)/reduced graphene oxide(rGO)/carbon nanotube (MWCNT) papers-like and the effect on electrical conductivities after annealing treatment. The pure GO and the hybrid papers were obtained by vacuum filtration and submitted to mild thermal annealing at 400 °C under an argon atmosphere. Analyses comparing the carbon paper-like materials before and after thermal treatment were done by thermogravimetric analysis (TGA), Raman spectroscopy, scanning electron microscopy (SEM), and electrical conductivity measurements. The characterization results show the annealing process effect on the morphology of paper materials. The GO papers and the hybrid (GO/rGO/MWCNT) exhibited good free-standing structure properties. The SEM results suggest the formation of gas void due to the thermal treatment. TGA and Raman results showed the thermal reduction and restoration of the carbon sp2 network of the graphene oxide induced by thermal treatment. The thermal treatment was responsible for changing the almost insulator characteristic of free-standing pure GO paper, achieving an electrical conductivity of 752 S/m, and improving 45% of the free-standing hybrid carbon nanomaterials papers (GO/rGO/MWCNT) electrical conductivity, achieving the value of 1020 S/m.

ABSTRACT Ferruginous Rocky Outcrops have high levels of species richness and endemism, but have been threatened by several anthropic actions, especially mining. Eragrostis polytricha, a common grass species in the vegetation of these outcrops, has shown promising features for use in the recovery of mining areas. However, in order to fully understand the species’ potential for such use, its requirements for germination, seed dormancy break and seedling development must be determined. Thus, we aimed to: (1) assess the temperature conditions needed for seeds of E. polytricha to germinate; (2) evaluate the effects of KNO₃ in breaking seed dormancy; and (3) analyze the germination efficiency of seeds that are still in spikelets. The experiment included seven treatments: 15-35 ºC with KNO₃, 20-30 ºC with KNO₃, 15 ºC with KNO₃, 25 ºC with KNO₃, 35 ºC with KNO₃, 20-30 ºC with water, and 20-30 ºC with KNO₃ using spikelets. The treatments with alternating temperatures associated with KNO3 yielded the highest germination rates, suggesting that these two factors combined can break seed dormancy. Seeds inside spikelets exhibited a high germination percentage, and thus represent an interesting alternative for seedling production.

Nove espécies de cinco famílias de plantas hospedeiras lactíferas foram examinadas, a procura de lagartas, em uma área de cerca de 4 ha de cerrado sensu stricto na Fazenda Água Limpa da Universidade de Brasília, DF, Brasil, de agosto de 1995 a maio de 1997. Foram realizados 5.540 censos e em menos de 5% das plantas hospedeiras foram encontradas lagartas. Todas as lagartas encontradas foram criadas em condições de laboratório. No laboratório emergiram 55 espécies de 15 famílias de Lepidoptera. As famílias mais comuns foram Pyralidae, Geometridae, Elachistidae, Megalopygidae e Limacodidae. Do total de 55 espécies mais de 40% são certamente polífagas. Entretanto, 21 espécies podem ser consideradas raras com menos de quatro ocorrências, o que impede uma análise de dieta. De um modo geral a presença de látex nas plantas hospedeiras parece afetar a abundância e a riqueza de espécies de Lepidoptera. Espécies de Lepidoptera de famílias distantes filogeneticamente foram encontradas alimentando-se dessas plantas lactíferas, o que corrobora a sugestão de que comportamentos específicos desenvolvidos para alimentar-se de plantas com látex tenham evoluido várias vezes entre os lepidópteros.

Nine lactiferous plants of five families were examined for caterpillars in a 4 ha cerrado sensu stricto (savanna-like vegetation) area of the University of Brasília Experimental Farm (DF, Brazil), from August 1995 to May 1997. In 5,540 censuses, less than 5% of the plants hosted caterpillars. All the caterpillars found, a total of 55 species in 15 families were reared under laboratory conditions. Pyralidae, Geometridae, Elachistidae, Megalopygidae, and Limacodidae were the richest caterpillar families recorded. Of the 55 species, more than 40% were polyphagous, feeding on different host plant families, while 21 were considered rare species with less than four records during the study period. The species' rareness did not permit any analysis of diet breadth. The presence of latex in the host plants seems to affect both the proportion of host plants with caterpillars (abundance) and the caterpillar species richness. The habit of eating plants that characteristically produce latex occurs in several distantly-related lepidopteran families. The results support the argument that specific behaviors to circumvent plant latex defense may have arisen independently many times in the Lepidoptera.