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TiO2 semiconductor nanoparticles (NPs) in the anatase phase have presented limitations of application in photocatalysis, mainly due to the fast recombination of photoexcited electrons. The combination with other nanoparticles/nanostructures has been shown to be a promising solution for increasing photocatalytic efficiency. In this work, titanium dioxide (TiO2) nanoparticles in different crystalline phases were prepared through a rapid microwave-assisted synthesis and modified by silver nanoparticles (Ag) and graphene oxide (GO). The samples were characterized by x-ray diffraction, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy and gas adsorption. Crystalline anatase NPs were obtained in basic conditions (pH = 8) while in acidic conditions (pH = 1), single-crystalline rutile NPs were formed. Different previous drying methods: oven and freeze-drying used led to a differentiation in crystallographic phases obtained. Anatase TiO2 and anatase-rutile mixture NPs calcined at 400 °C showed properties as high specific surface area, crystallinity and reduced electron–hole recombination which contributed to an enhanced photocatalytic activity, when compared to the Degussa P25 photoactivity. The effect of silver nanoparticles and GO addition to TiO2 nanopowder was evaluated for photocatalysis activity. An improvement in the methylene blue and rhodamine B dyes photodegradation was observed for both anatase and rutile TiO2 nanocomposites. We noted that anatase TiO2 nanoparticles degraded 53% of rhodamine B, and when functionalized with GO, the photodegradation increased to 69%. Comparatively, the addition of silver nanoparticles to anatase TiO2 increased the dye degradation to 97% in 180 min. Hence, we revel that in the TiO2 nanocomposites, silver nanoparticles showed better interfacial charge transfer than GO, contributing more effectively to the dye photodegradation process.

Understanding elasmobranch reproductive biology is necessary for species conservation. Multiple paternity (MP) has been reported for elasmobranchs, and this study investigates the reproductive aspects and mating system (paternity genetic analyses) for Squalus albicaudus. Thirteen pregnant females were analysed concerning reproductive parameters, and the mating system was assessed for nine females and their litters. The study found a mean fecundity of 2.84 pups per litter without correlation between total female length and the number of embryos per litter. One litter showed evidence of MP, indicating the presence of polyandrous behaviour of the species.

The accelerated artificial aging with ultraviolet radiation, viscosity, density, no-pick-up time, flexibility, and abrasion resistance of lignin-modified road marking paint were evaluated. The addition of lignin did not cause significant changes in the physical chemistry, flexibility and no-pick-time test compared to the precursor paint. The addition of 1.00 wt. % of lignin increased the abrasion resistance by 36%. The Fourier Transform Infrared technique performed before and after exposure to Weather-o-meter aging chamber has shown the cleavage of ester groups that are present in acrylic-based resin. The incorporation of 0.10 wt.%, 0.25 wt.%, and 1.00 wt.% increased the photodegradation resistance of the road marking paint inhibiting the ester group and side-chain scissions, since the C-O and C=O band intensity increased after irradiation. The introduction of lignin delayed the yellowing of the aged samples and improved mechanical and photophysical properties besides being a good strategy for the biomass waste utilization of the paper industry.

Rhinoptera bonasus is a bento-pelagic and highly migratory species occurring from southern United States to northern Argentina. Due to overfishing effects, R. bonasus is currently at risk, classified by the IUCN Red List as vulnerable. Considering the lack of molecular data available for R. bonasus, this study aimed to describe the genetic variability and population structure of specimens sampled from three Brazilian coast ecoregions (Amazon ecoregion, Pará; Northeastern ecoregion, Pernambuco and Southeastern ecoregion, Rio de Janeiro, São Paulo and Santa Catarina), through five polymorphic microsatellite markers. Here testing the panmixia hypothesis for Brazilian ecoregions and test natal philopathy. A total of 69 analyzed specimens revealed individual and significant genetic differentiation between the sampled locations. Φ ST (0.12), PCA, DAPC and Bayesian analyses of the genetic population structure revealed at least two distinct genetic R. bonasus groupings. IBD tests were significant, indicating a correlation between genetic and geographical distance among populations, which can be explained by reproductive philopatric behavior. Philopatric behavior associated with R. bonasus mobility may influence the differentiation values observed for all loci in the investigated samples.

RESUMO O óxido de grafeno (GO) é um nanomaterial de carbono que apresenta propriedades únicas e dentre elas, a excelente condutividade térmica que pode ser explorada em nanocompósitos, como também em nanofluidos. O etilenoglicol (ETG) é um fluido de troca térmica que pode ter suas propriedades térmicas potencializadas pela adição de GO. Porém, tanto o nível de dispersão de GO quanto a reologia da suspensão, podem influenciar as características dos nanofluidos, como o fluxo, a estabilidade e a transferência térmica. Assim, o estudo reológico de nanofluidos ETG/GO é importante para o entendimento da estabilidade coloidal dessas suspensões e do potencial de aplicação como fluido de transferência térmica. Neste trabalho, GO sintetizado pelo método de Hummers modificado foi utilizado para preparar nanofluidos ETG/GO para estudos reológicos. Técnicas instrumentais como microscopia eletrônica de varredura (MEV), difração de raios X (DRX), espectroscopia na região do infravermelho por transformada de Fourier (FTIR), microscopia eletrônica de transmissão (MET) e termogravimetria (TGA), confirmaram a obtenção de GO com cerca de 4 folhas de grafeno e funcionalização de 38% com grupos oxigenados. A superfície hidrofílica do GO permitiu que as nanofolhas tivessem boa compatibilidade com o ETG. Foram investigados os perfis de curvas de fluxo das suspensões de nanofluidos ETG/GO, e estes foram classificados como: não Newtonianos e pseudoplásticos pelo modelo de Ostwald-de Waele. A inserção de GO ao ETG, aumentou a viscosidade e o módulo de armazenamento (G’) em 21% e 8%, respectivamente. As propriedades aprimoradas evidenciam o potencial de uso de nanofluidos de GO para aplicações em sistemas térmicos.