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Efeito da abundância das aves granívoras sobre a predação de sementes pós-dispersão em fragmentos florestais da Mata Atlântica
(Universidade Federal de São Carlos, 2012-08-03) Menezes, Gregório dos Reis; Hasui, Erica; Christianini, Alexander Vicente; https://lattes.cnpq.br/2295622727813765; Silva, Fernando Rodrigues da; http://lattes.cnpq.br/8543094930527221; Ferreira, Marco Aurélio Pizo
Mineração de regras de associação sequenciais em séries temporais e visualização: aplicação em dados agrometeorológicos
(Universidade Federal de São Carlos, 2012-08-03) Cano, Marcos Daniel; Ribeiro, Marcela Xavier; https://lattes.cnpq.br/0300141044144026; https://lattes.cnpq.br/9695321755996994
Technological development brought improvements in the technology of climate sensors and Earth's surface image acquisition, gathering increasing amounts of data. Generally, when these data are submitted to mining algorithms, the output is the production of hundreds or even thousands of textual patterns, making the task of data analysis by the domain expert even harder. Hence, it is crucial, to support experts, the development of a tool that helps to identify and display patterns of interest. In this context, this research project at Master Science level aims to develop a technique for mining association rules in time series allowing agrometeorological data analysis over time.
Riqueza e abundância de espécies em diferentes compartimentos da comunidade vegetal no gradiente fisionômico do Cerrado em Assis, SP
(Universidade Federal de São Carlos, 2012-08-03) Neri, Ana Carolina Abrão; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/7641978829218060
Fire protection has caused ongoing changes in savannas throughout the world, with the expansion of the woody component over more open vegetation. Although these changes have been documented at the landscape level, some questions regarding changes in the floristic composition of communities and the regeneration mechanisms present in different physiognomies remain. The aim of this study was to evaluate species richness and abundance in several components of the community (seed rain, seed bank, and the understory, intermediate, and upper strata) in a cerrado area after 50 years of fire protection. This research was developed along the physiognomic gradient (typical cerrado, dense cerrado and cerradão) existent at Assis Ecological Station, São Paulo state. Seed rain, seed bank, and floristic composition of the three strata were sampled in 30 20 x 50 m plots, 10 plots in each physiognomy. Differences between physiognomies and between seasons were analyzed by means of uni- and multivariate analysis of variance and by linear regression and correlation. Basal area was used as a surrogate of biomass along the physiognomic gradient. Species richness decreased across the whole community for the ground layer and intermediate layer along the successional gradient. In seed rain and seed bank, the floristic composition and abundance differed significantly between the three physiognomies. In seed rain, trees and saplings, mostly generalist species, represented the predominant growth forms, both in relative abundance, as in richness. In the seed bank, herbaceous species presented the highest values for richness and abundance in all physiognomies. The seed rain and seed bank are important as regeneration strategies for a group of species, usually generalists. The homogenization of vegetation structure and floristic composition puts under question the management strategies currently employed in areas designed for Cerrado conservation. Considering that Cerrado fragmentation has concentrated its gene pool in small, isolated remnants and that some plant and animal species are restricted to more open physiognomies, a more refined discussion of the implications that management regimes may have on these communities is essential.
Desenvolvimento de nanoblendas poliméricas PMMA/SAN
(Universidade Federal de São Carlos, 2012-08-03) Ternes Neto, Alvaro; Hage Júnior, Elias; https://lattes.cnpq.br/1240692926327687; https://lattes.cnpq.br/0814243517392991
The motivation for this work was the idea that nanoblends are fundamentally dependent on the high interaction between the phases in the mixture. The strategy adopted in this study was based on the use of two polymers that have a miscibility window, which allows the establishment of an immiscibility condition very close to the limit of this window, providing low interfacial tension between phases. Nanoblends of poly(methyl methacrylate) (PMMA) as the matrix and poly(styrene-co-acrylonitrile) (SAN) as the nanophase were obtained by blending in a twin screw extruder. The compatibilization between the phases was accomplished through the incorporation of the terpolymer (MGE) synthesized from the monomers methyl methacrylate (MMA), glycidyl methacrylate (GMA) and ethyl acrylate (EA). The morphology of the blends was characterized by transmission electron microscopy (TEM). The transparency of the blends and pure polymers was quantified by transmittance of visible light. Tests such as torque rheometry, capillary rheometry, tensile strength and chemical resistance to solvents were also performed. Nanoblends with 1 and 3 wt% of the dispersed phase were obtained in the absence of MGE. The introduction of the terpolymer allowed a significant reduction of the SAN phase for compositions with 5 and 10% by weight. Through this reduction blends with 5 wt% of SAN reach the nanoscale. It was found that blends transparency is directly related to the dispersed phase mass fraction. Blends mechanical properties were close to those of the PMMA. Blends and pure polymers did not swell by the solvents chosen.