17 research outputs found

    Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

    No full text
    International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12‚ÄČyears, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of ‚Äúscientific reductionism‚ÄĚ, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

    Development of a standard bench-scale cell for electrochemical studies on inert anodes. Inert Anode/Cathode Program

    No full text
    Objective of this work was to develop a standard bench-scale cell for performing short-term ac and dc polarization studies on inert anode candidate materials in molten cryolite. Two designs for electrochemical cells were developed and successfully evaluated in short-term experiments. Both cells consisted on the inert anode as a small cylindrical specimen partially sheathed in alumina, an Al/Al/sub 2/O/sub 3/ reference electrode, and a cryolite bath saturated in alumina. The difference between the two cells was in the design of the cathode. One cell used a bare solid metal cathode; the other used an aluminum pad similar to the Hall-Heroult configuration


    No full text

    A comparative EIS study on cermet and platinum anodes for the electrolytic production of aluminum

    No full text
    Electrochemical impedance spectra (EIS) of NiO-NiFe{sub 2}O{sub 4}-Cu cermet anodes in alumina-saturated molten cryolite at anodic potentials above the decomposition potentials above the decomposition potential of alumina exhibited a loop with a characteristic frequency of about 1 Hz. A similar feature was observed using platinum anodes under the same experimental conditions. Analysis of these data suggests the loop was due to gas bubbling. Features associated with charge-transfer processes were not sufficiently resolved to determine the corrosion properties of the cermet anode

    Methods for Characterising Microphysical Processes in Plasmas

    Full text link

    Irradiation effects on the electrochemistry and corrosion resistance of stainless steel

    No full text
    Nickel-ion irradiation at 500{degrees}C is shown to have a strong effect on the surface electrochemistry and intergranular corrosion of stainless steel. Measured current densities in a 1N H{sub 2}SO{sub 4} solution at room temperature are increased at active-passive, passive, and transpassive potentials. Irradiation effects on the current decay behavior and susceptibility to intergranular corrosion were similar for a microcrystalline, fine-grained stainless alloy and for a very large-grained stainless steel. Radiation-induced segregation at the surface is believed to promote higher currents, whereas segregation at grain boundaries prompts intergranular attack. Analytical electron microscopy measurements reveal silicon enrichment and chromium depletion at internal interfaces in irradiated specimens. Silicon enhances dissolution at transpassive potentials, whereas chromium depletion does the same at active-passive and passive potentials