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Modificação e caracterização da superfície do aço inoxidável Martensítico AISI 410
(Universidade Federal de São Carlos, 2010-04-29) Bincoleto, Alexandre Vinicius Leite; Nascente, Pedro Augusto de Paula; https://lattes.cnpq.br/1387043320265189; https://lattes.cnpq.br/2903700887151032
This work deals about the surface modification of the AISI 410 martensitic stainless steel. The modification of steel surfaces is important for the improvement of its mechanical and tribological properties. Among the modification processes, there are coating, deposition of thin films, and ion implantation. The AISI 410 stainless steel is widely applied by manufacturers of steam turbine for the production of blades, rods, and valves, which are the components that suffer more the abrasion by water vapor. This work compares the main surface modifications employed in the AISI 410 stainless steel in order to define which the best deposition processes are regarding their final application (nitriding, carbonitriding, and boronizing). The structures, the morphologies, and the chemical compositions of the modified surfaces had been characterized by XRD. Also optical microscopy was used for the analysis of the microstructural modifications and measurement of the surface hardness.
Efeitos da distribuição de manchas de folhas na estrutura de macroinvertebrados de riachos
(Universidade Federal de São Carlos, 2010-04-29) Hanashiro, Fábio Toshiro Taquicava; Tanaka, Marcel Okamoto; https://lattes.cnpq.br/2768658925977757; https://lattes.cnpq.br/6370839955073511
To understand the effects of spatial heterogeneity on the processes that determine the distribution of organisms in low-order streams, in the present study we asked the following question: do the composition and spatial arrangement of leaf litter patches at the scale of streambed landscapes influence the structure and composition of aquatic macroinvertebrate communities? We evaluated substrate organization in two distinct phases: an initial description of the streambeds using landscape ecology techniques, and a second, experimental phase studying the response of aquatic macroinvertebrates to manipulated distributions of the substrate. The results of the descriptive phase showed the importance of leaf litter substrate influencing taxon richness, diversity, evenness, and abundance; further, the division of the habitat in patches was also important to structure the macroinvertebrate communities. The experimental manipulation showed that resource aggregation influences the colonization of the community, mainly in the early periods (8 days). In general, the influence of resource spatial distribution had different effects between the two approaches used, probably due to differences in patch size and quality. The results of the present study can contribute to a better comprehension of the mechanisms structuring the communities of aquatic macroinvertebrates, and to the improvement of sampling techniques and stream restoration projects.