Abstract Environmental friendliness and cost demand the development of lignin-modified phenolic (LPF) resins for application as a binder for carbon-containing refractories (CCRs) production. Moreover, the in-situ graphitization of such resins can produce crystalline carbon, which is an essential component of CCRs. Consequently, this study investigated LPF resins graphitization using ferrocene, boron oxide and boric acid. The modified resins were synthesized using thermally treated kraft lignin based on 1.5 formaldehyde to phenol molar ratio and with up to 30 wt.% lignin as phenol replacement. The resins chemical composition and the structural organization and oxidation resistance of carbons derived from the plain resins and those containing the graphitizing additives were determined. The results showed that ferrocene and the boron compounds could induce graphitic carbon generation when carbonizing LPF resins at 1500 °C for 5 hours. The best graphitization level (73%) was achieved when 10 wt.% boric acid was added to the resin produced with 20 wt.% lignin. Regarding the formulations containing ferrocene, the highest amount of graphitic carbon (48%) was generated when 5 wt.% of this additive was added to the resin synthesized with 10 wt.% lignin. The carbons derived from the formulations containing boron oxide presented the best oxidation resistance.

RESUMO A vegetação de restinga é uma formação típica de ecossistemas costeiros de alta relevância ecológica. Dessa forma, o objetivo do estudo foi descrever a composição florística e estrutural de um fragmento de restinga herbáceo-subarbustiva localizada em Balneário Esplanada, no município de Jaguaruna, sul do Estado de Santa Catarina. Foram instaladas 20 parcelas de 4 m2 equidistantes quatro metros entre si, totalizando 80 m2 de área amostral. A cobertura de cada espécie foi estimada pela escala de Causton. Foram amostrados 90 indivíduos distribuídos em 13 famílias botânicas, 21 gêneros e 21 espécies. As famílias com maior riqueza foram Asteraceae, Poaceae, Boraginaceae e Solanaceae. As espécies mais frequentes foram Panicum racemosum e Hydrocotyle bonariensis, com VI igual a 37,5 e 23,5, respectivamente. Para a estrutura comunitária houve sete classes de altura, sendo os primeiros estratos os mais ricos e a classe 1 com o maior número de espécies. A diversidade de Shannon e equabilidade de Pielou foram 2,67 e 0,59, respectivamente.

ABSTRACT The sandbank vegetation is a typical coastal ecosystem with a high ecological importance. The objective of this study was to describe the floristic and structural composition of an herbaceous sub shrub Restinga fragment located in Balneário Esplanada, municipality of Jaguaruna, in the south of Santa Catarina State. Twenty plots of 4m2 equally spaced four meters from each other were installed, totaling 80m2 of sampled area. The coverage of each species was estimated by the Causton scale. Ninety individuals of 13 botanical families, 21 genera and 21 species were sampled. The richest families were Asteracae, Poaceae, Boraginaceae and Solanaceae. The most predominant species were Panicum racemosum and Hydrocotyle bonariensis, with VI equal to 37.5 and 23.5, respectively. Within the community structure, there were seven height classes, the first strata being the richest, and the class 1 with the largest number of species. The diversity of Shannon and Pielou equability were 2.67 and 0.59, respectively.

AbstractThis work aims to evaluate the melting temperature and wetting behavior of AlN/Re2O3 (Re = Dy, Yb) mixtures when in contact with SiC substrates at high temperatures, in order to define whether these compounds can be further used to induce a more effective liquid phase sintering of SiC-based products. The prepared samples were placed on SiC plates and thermally treated up to 1900 °C under argon. The melting point and spreading evolution of different compositions of AlN/Re2O3 on SiC were determined by analyzing images captured as a function of the heating temperature. The contact angle and melting point were measured using the ImageJ software and according to DIN 51730, respectively. Based on the obtained wetting curves, all evaluated conditions resulted in the decrease of the contact angle values with temperature. The mixtures presenting improved wetting (θ ~ 1° and 3°) on SiC plates were the ones above the selected eutectic point.