Production And Electrochemical Properties Of Limn2o4 Thin Films Via A Proteic Sol-gel Process

LiMn2O4 thin films were obtained by a proteic sol-gel process using the coconut water as solvent of salts. X-ray diffractions showed a spinel phase with Fd3m space group. The capacity of lithium charge was 37 mAh/cm2-μm for thin film annelead at 800°C.20-21242246Thackeray, M.M., Yang, S.-H., (1998) Electrochemical and Solid State Letters, 1, p. 7Lee, Y.-S., Sun, Y.-K., Nahm, K.-S., (1998) Solid States Ionics, 109, p. 285Choi, S., Manthiram, A., (2000) Journal of Electrochemical Society, 147, p. 1623Gummow, R.J., De Kock, A., Thackeray, M.M., (1994) Solid States Ionics, 69Park, Y.J., Kim, J.G., Kim, M.K., (1998) Journal of Power Sources, 76, p. 41Macedo, M.A., (1998), Brazilian Patent , 9804719.1Duque, J.G., Macedo, M.A., Moreno, N.O., (2000) Physica Status Solidi B, 200, p. 413Duque, J.G., Macedo, M.A., Moreno, N.O., Lopez, J.L., Pfanes, H.D., (2001) Journal of Magnetismand Magnetic Materials, 226-232, p. 1424Montes, P.J., Valério, M.E.G., Macedo, M.A., Cunha, F., Sasaki, J.M., (2003) Microelectronics Journal, 34, p. 557Meneses, C.T., Macedo, M.A., Vicentin, F.C., (2003) Microelectronics Journal, 34, p. 561Santos, J.V.A., Macedo, M.A., Cunha, F., Sasaki, J.M., Duque, J.G.S., (2003) Microelectronics Journal, 34, p. 565Palacín, M.R., Tarascon, J.M., (2000) Journal of Electrochemical Society, 147, p. 84

Preparation Of Nife 2o 4 Thin Films By A New Route Sol-gel

NiFe 2O 4 thin films were prepared using new route sol-gel process. The films were heated at 300°C for 5 min. The magnetic properties were also determined at room temperature by applying magnetic fields up to 4 kOe perpendicular to the surface of the samples by means of a SQUID magnetometer.Chen, K.C., (1986) Mater. Res. Soc. Symp. Porc., 73, p. 731Miroslav, S., Ladislav, P., (1991) Ceramics International, 21, p. 21Duque, J.G.S., (2000) Phys. Stat. Sol. (b), 220, p. 413Duque, J.G.S., (2001) J. Magn. Magn. Mater., 226-230, p. 1424Guyot, M., (1996) Applied Surface Science, 96-98, p. 80

The effects of sooty mold on photosynthesis and mesophyll structure of mahogany (Swietenia macrophylla King., Meliaceae) Efeitos da fumagina sobre a fotossíntese e a estrutura do mesofilo de mogno

The aim of present study was to evaluate the effects of the sooty mold on anatomy and photochemical activity of mahogany (Swietenia macrophylla) leaves. The photochemical features of shade-developed leaves with or without sooty mold were compared to those of sun leaves using chlorophyll a fluorescence measurements. Leaf anatomy was also evaluated using conventional techniques. The degree of blockage of the photosynthetic active photon flux density (PPFD) by sooty mold and its effect on photochemistry were evaluated. Sun leaves showed thick mesophyll with palisade parenchyma disposed in a uniseriate layer, whereas shade leaves showed narrow mesophyll, independently of sooty mold presence. The effective quantum yield (deltaF/Fm') and the apparent electron transport rate (ETR) of sun leaves were higher than those of shade leaves. The values of ETR suggested that photochemistry saturation occurred at lower PPFD in shade-grown plants. Lower values of the deltaF/Fm' and, consequently, lower values of ETR were observed in leaves with sooty mold. A reduction of 40% of the incident light was seen due to physical blockage by sooty mold which is presumably responsible for an additional decrease of ETR values. Our data indicated that sooty mold did not directly damage the leaf, but reduce leaf photochemistry capacity, by decreasing light availability.<br>O objetivo do presente estudo foi avaliar os efeitos da fumagina na anatomia e a atividade fotoquímica em folhas de mogno (Swietenia macrophylla King., Meliaceae). Folhas com e sem fumagina desenvolvidas na sombra foram comparadas com as de folhas de sol, para verificar as diferenças em parâmetros fotoquímicos utilizando-se medidas de fluorescência. As amostras de folhas destinadas a estudos anatômicos foram processadas segundo técnicas convencionais. A intensidade de bloqueio da radiação densidade de fótons fotossinteticamente ativos (DFFA) pela fumagina e seu efeito sobre a atividade fotoquímica foram avaliados. As folhas de sol têm mesofilo espesso e parênquima paliçádico unisseriado enquanto nas folhas de sombra o mesofilo é delgado, independentemente da presença ou não de fumagina. O rendimento quântico efetivo (deltaF/Fm') e a taxa aparente de transporte de elétrons (ETR) das folhas de sol foram superiores às das folhas de sombra. Os valores de ETR sugerem que, nas plantas crescidas na sombra, a saturação da atividade fotoquímica ocorre em menores valores de DFFA. Observaram-se menores valores de deltaF/Fm' nas folhas com fumagina e, conseqüentemente menores valores de ETR. A presença de fumagina promoveu bloqueio de 40% na luz incidente e, conseqüentemente, presume-se um decréscimo adicional nos valores de ETR. Pelos dados, verifica-se que a presença de fumagina não promoveu danos diretos nas folhas, mas reduz a capacidade fotoquímica por diminuir a disponibilidade de luz

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

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 years, 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 “scientific reductionism”, 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