Abstract Diatoms are successful in occupying a wide range of ecological niches and biomes along the global ocean. Although there is a recognized importance of diatoms for the Southern Ocean ecosystems and biogeochemical cycles, the current knowledge on their ecology and distribution along the impacted Antarctic coastal regions remains generalized at best. HPLC–CHEMTAX approaches have been extensively used to this purpose, providing valuable information about the whole phytoplankton community, even for those small-size species which are normally difficult to identify by light microscopy. Despite that, the chemotaxonomic method has reserved minimal focus on great diversity of types associated with diatom genera or species. Here, we show a coupling between the key genera and the corresponding chemotaxonomic subgroup type-A or type-B of diatoms via HPLC–CHEMTAX and microscopic analysis, using chlorophyll–c 1 and chlorophyll–c 3 as biomarker pigments, respectively. The results demonstrated strong correlations for nine of the fifteen most abundant diatom genera observed along the Northern Antarctic Peninsula, from which five (four) were statistically associated with chlorophyll–c 1 (chlorophyll–c 3). Our study highlights the importance to observe diatoms in greater detail, beyond being only one functional group, for a better understanding on their responses under a climate change scenario.

This paper presents a comprehensive interface and electrochemical phenomena review of different anodes for SOFC. In this way, it was possible to select some mixed electronic and ionic conductor materials alternatives to the conventional anode, Ni-YSZ conductor. New materials must present a satisfactory electronic and ionic conductivity at intermediate temperatures, be able to operate under different types of hydrocarbon fuels without deactivation, present stability under redox cycles and thermal expansion compatible with the other materials. Among all new materials, Sr0.86Y0.08TiO3, a Y-doped strontium titanate (YST), presented the highest measured conductivity, of 82 S cm-1 at 800 °C. In addition, this material showed excellent stability time and coefficient of thermal expansion compatible with materials used as cathode, strontium-doped lanthanum manganite and electrolyte, yttria stabilized zirconia. SrTiO3 (ST) compounds synthesized by solid-state reaction method, calcined, and sintered to obtain undoped (ST), 4% (YST04) and 8% (YST08) of Y-dopant and as a heterojunction with yttria-stabilized zirconia (YST08/YSZ). It was observed that calcination under Ar/5%H2 atmosphere has increased the dopant maximum concentration in the SrTiO3 cubic crystal structure when compared to inert atmosphere. When the Y solubility limit was exceeded, a pyrochlore phase Y2Ti2O7 was formed on the intergranular region due to the deficiency of oxygen vacancies, especially in the presence of inert atmosphere.